1/* Functions related to building classes and their related objects. 2 Copyright (C) 1987, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 3 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. 4 Contributed by Michael Tiemann (tiemann@cygnus.com) 5 6This file is part of GCC. 7 8GCC is free software; you can redistribute it and/or modify 9it under the terms of the GNU General Public License as published by 10the Free Software Foundation; either version 2, or (at your option) 11any later version. 12 13GCC is distributed in the hope that it will be useful, 14but WITHOUT ANY WARRANTY; without even the implied warranty of 15MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16GNU General Public License for more details. 17 18You should have received a copy of the GNU General Public License 19along with GCC; see the file COPYING. If not, write to 20the Free Software Foundation, 51 Franklin Street, Fifth Floor, 21Boston, MA 02110-1301, USA. */ 22 23 24/* High-level class interface. */ 25 26#include "config.h" 27#include "system.h" 28#include "coretypes.h" 29#include "tm.h" 30#include "tree.h" 31#include "cp-tree.h" 32#include "flags.h" 33#include "rtl.h" 34#include "output.h" 35#include "toplev.h" 36#include "target.h" 37#include "convert.h" 38#include "cgraph.h" 39#include "tree-dump.h" 40 41/* The number of nested classes being processed. If we are not in the 42 scope of any class, this is zero. */ 43 44int current_class_depth; 45 46/* In order to deal with nested classes, we keep a stack of classes. 47 The topmost entry is the innermost class, and is the entry at index 48 CURRENT_CLASS_DEPTH */ 49 50typedef struct class_stack_node { 51 /* The name of the class. */ 52 tree name; 53 54 /* The _TYPE node for the class. */ 55 tree type; 56 57 /* The access specifier pending for new declarations in the scope of 58 this class. */ 59 tree access; 60 61 /* If were defining TYPE, the names used in this class. */ 62 splay_tree names_used; 63 64 /* Nonzero if this class is no longer open, because of a call to 65 push_to_top_level. */ 66 size_t hidden; 67}* class_stack_node_t; 68 69typedef struct vtbl_init_data_s 70{ 71 /* The base for which we're building initializers. */ 72 tree binfo; 73 /* The type of the most-derived type. */ 74 tree derived; 75 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived), 76 unless ctor_vtbl_p is true. */ 77 tree rtti_binfo; 78 /* The negative-index vtable initializers built up so far. These 79 are in order from least negative index to most negative index. */ 80 tree inits; 81 /* The last (i.e., most negative) entry in INITS. */ 82 tree* last_init; 83 /* The binfo for the virtual base for which we're building 84 vcall offset initializers. */ 85 tree vbase; 86 /* The functions in vbase for which we have already provided vcall 87 offsets. */ 88 VEC(tree,gc) *fns; 89 /* The vtable index of the next vcall or vbase offset. */ 90 tree index; 91 /* Nonzero if we are building the initializer for the primary 92 vtable. */ 93 int primary_vtbl_p; 94 /* Nonzero if we are building the initializer for a construction 95 vtable. */ 96 int ctor_vtbl_p; 97 /* True when adding vcall offset entries to the vtable. False when 98 merely computing the indices. */ 99 bool generate_vcall_entries; 100} vtbl_init_data; 101 102/* The type of a function passed to walk_subobject_offsets. */ 103typedef int (*subobject_offset_fn) (tree, tree, splay_tree); 104 105/* The stack itself. This is a dynamically resized array. The 106 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */ 107static int current_class_stack_size; 108static class_stack_node_t current_class_stack; 109 110/* The size of the largest empty class seen in this translation unit. */ 111static GTY (()) tree sizeof_biggest_empty_class; 112 113/* An array of all local classes present in this translation unit, in 114 declaration order. */ 115VEC(tree,gc) *local_classes; 116 117static tree get_vfield_name (tree); 118static void finish_struct_anon (tree); 119static tree get_vtable_name (tree); 120static tree get_basefndecls (tree, tree); 121static int build_primary_vtable (tree, tree); 122static int build_secondary_vtable (tree); 123static void finish_vtbls (tree); 124static void modify_vtable_entry (tree, tree, tree, tree, tree *); 125static void finish_struct_bits (tree); 126static int alter_access (tree, tree, tree); 127static void handle_using_decl (tree, tree); 128static tree dfs_modify_vtables (tree, void *); 129static tree modify_all_vtables (tree, tree); 130static void determine_primary_bases (tree); 131static void finish_struct_methods (tree); 132static void maybe_warn_about_overly_private_class (tree); 133static int method_name_cmp (const void *, const void *); 134static int resort_method_name_cmp (const void *, const void *); 135static void add_implicitly_declared_members (tree, int, int); 136static tree fixed_type_or_null (tree, int *, int *); 137static tree resolve_address_of_overloaded_function (tree, tree, tsubst_flags_t, 138 bool, tree); 139static tree build_simple_base_path (tree expr, tree binfo); 140static tree build_vtbl_ref_1 (tree, tree); 141static tree build_vtbl_initializer (tree, tree, tree, tree, int *); 142static int count_fields (tree); 143static int add_fields_to_record_type (tree, struct sorted_fields_type*, int); 144static void check_bitfield_decl (tree); 145static void check_field_decl (tree, tree, int *, int *, int *); 146static void check_field_decls (tree, tree *, int *, int *); 147static tree *build_base_field (record_layout_info, tree, splay_tree, tree *); 148static void build_base_fields (record_layout_info, splay_tree, tree *); 149static void check_methods (tree); 150static void remove_zero_width_bit_fields (tree); 151static void check_bases (tree, int *, int *); 152static void check_bases_and_members (tree); 153static tree create_vtable_ptr (tree, tree *); 154static void include_empty_classes (record_layout_info); 155static void layout_class_type (tree, tree *); 156static void fixup_pending_inline (tree); 157static void fixup_inline_methods (tree); 158static void propagate_binfo_offsets (tree, tree); 159static void layout_virtual_bases (record_layout_info, splay_tree); 160static void build_vbase_offset_vtbl_entries (tree, vtbl_init_data *); 161static void add_vcall_offset_vtbl_entries_r (tree, vtbl_init_data *); 162static void add_vcall_offset_vtbl_entries_1 (tree, vtbl_init_data *); 163static void build_vcall_offset_vtbl_entries (tree, vtbl_init_data *); 164static void add_vcall_offset (tree, tree, vtbl_init_data *); 165static void layout_vtable_decl (tree, int); 166static tree dfs_find_final_overrider_pre (tree, void *); 167static tree dfs_find_final_overrider_post (tree, void *); 168static tree find_final_overrider (tree, tree, tree); 169static int make_new_vtable (tree, tree); 170static int maybe_indent_hierarchy (FILE *, int, int); 171static tree dump_class_hierarchy_r (FILE *, int, tree, tree, int); 172static void dump_class_hierarchy (tree); 173static void dump_class_hierarchy_1 (FILE *, int, tree); 174static void dump_array (FILE *, tree); 175static void dump_vtable (tree, tree, tree); 176static void dump_vtt (tree, tree); 177static void dump_thunk (FILE *, int, tree); 178static tree build_vtable (tree, tree, tree); 179static void initialize_vtable (tree, tree); 180static void layout_nonempty_base_or_field (record_layout_info, 181 tree, tree, splay_tree); 182static tree end_of_class (tree, int); 183static bool layout_empty_base (tree, tree, splay_tree); 184static void accumulate_vtbl_inits (tree, tree, tree, tree, tree); 185static tree dfs_accumulate_vtbl_inits (tree, tree, tree, tree, 186 tree); 187static void build_rtti_vtbl_entries (tree, vtbl_init_data *); 188static void build_vcall_and_vbase_vtbl_entries (tree, vtbl_init_data *); 189static void clone_constructors_and_destructors (tree); 190static tree build_clone (tree, tree); 191static void update_vtable_entry_for_fn (tree, tree, tree, tree *, unsigned); 192static void build_ctor_vtbl_group (tree, tree); 193static void build_vtt (tree); 194static tree binfo_ctor_vtable (tree); 195static tree *build_vtt_inits (tree, tree, tree *, tree *); 196static tree dfs_build_secondary_vptr_vtt_inits (tree, void *); 197static tree dfs_fixup_binfo_vtbls (tree, void *); 198static int record_subobject_offset (tree, tree, splay_tree); 199static int check_subobject_offset (tree, tree, splay_tree); 200static int walk_subobject_offsets (tree, subobject_offset_fn, 201 tree, splay_tree, tree, int); 202static void record_subobject_offsets (tree, tree, splay_tree, bool); 203static int layout_conflict_p (tree, tree, splay_tree, int); 204static int splay_tree_compare_integer_csts (splay_tree_key k1, 205 splay_tree_key k2); 206static void warn_about_ambiguous_bases (tree); 207static bool type_requires_array_cookie (tree); 208static bool contains_empty_class_p (tree); 209static bool base_derived_from (tree, tree); 210static int empty_base_at_nonzero_offset_p (tree, tree, splay_tree); 211static tree end_of_base (tree); 212static tree get_vcall_index (tree, tree); 213 214/* Variables shared between class.c and call.c. */ 215 216#ifdef GATHER_STATISTICS 217int n_vtables = 0; 218int n_vtable_entries = 0; 219int n_vtable_searches = 0; 220int n_vtable_elems = 0; 221int n_convert_harshness = 0; 222int n_compute_conversion_costs = 0; 223int n_inner_fields_searched = 0; 224#endif 225 226/* Convert to or from a base subobject. EXPR is an expression of type 227 `A' or `A*', an expression of type `B' or `B*' is returned. To 228 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for 229 the B base instance within A. To convert base A to derived B, CODE 230 is MINUS_EXPR and BINFO is the binfo for the A instance within B. 231 In this latter case, A must not be a morally virtual base of B. 232 NONNULL is true if EXPR is known to be non-NULL (this is only 233 needed when EXPR is of pointer type). CV qualifiers are preserved 234 from EXPR. */ 235 236tree 237build_base_path (enum tree_code code, 238 tree expr, 239 tree binfo, 240 int nonnull) 241{ 242 tree v_binfo = NULL_TREE; 243 tree d_binfo = NULL_TREE; 244 tree probe; 245 tree offset; 246 tree target_type; 247 tree null_test = NULL; 248 tree ptr_target_type; 249 int fixed_type_p; 250 int want_pointer = TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE; 251 bool has_empty = false; 252 bool virtual_access; 253 254 if (expr == error_mark_node || binfo == error_mark_node || !binfo) 255 return error_mark_node; 256 257 for (probe = binfo; probe; probe = BINFO_INHERITANCE_CHAIN (probe)) 258 { 259 d_binfo = probe; 260 if (is_empty_class (BINFO_TYPE (probe))) 261 has_empty = true; 262 if (!v_binfo && BINFO_VIRTUAL_P (probe)) 263 v_binfo = probe; 264 } 265 266 probe = TYPE_MAIN_VARIANT (TREE_TYPE (expr)); 267 if (want_pointer) 268 probe = TYPE_MAIN_VARIANT (TREE_TYPE (probe)); 269 270 gcc_assert ((code == MINUS_EXPR 271 && SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), probe)) 272 || (code == PLUS_EXPR 273 && SAME_BINFO_TYPE_P (BINFO_TYPE (d_binfo), probe))); 274 275 if (binfo == d_binfo) 276 /* Nothing to do. */ 277 return expr; 278 279 if (code == MINUS_EXPR && v_binfo) 280 { 281 error ("cannot convert from base %qT to derived type %qT via virtual base %qT", 282 BINFO_TYPE (binfo), BINFO_TYPE (d_binfo), BINFO_TYPE (v_binfo)); 283 return error_mark_node; 284 } 285 286 if (!want_pointer) 287 /* This must happen before the call to save_expr. */ 288 expr = build_unary_op (ADDR_EXPR, expr, 0); 289 290 offset = BINFO_OFFSET (binfo); 291 fixed_type_p = resolves_to_fixed_type_p (expr, &nonnull); 292 target_type = code == PLUS_EXPR ? BINFO_TYPE (binfo) : BINFO_TYPE (d_binfo); 293 294 /* Do we need to look in the vtable for the real offset? */ 295 virtual_access = (v_binfo && fixed_type_p <= 0); 296 297 /* Don't bother with the calculations inside sizeof; they'll ICE if the 298 source type is incomplete and the pointer value doesn't matter. */ 299 if (skip_evaluation) 300 { 301 expr = build_nop (build_pointer_type (target_type), expr); 302 if (!want_pointer) 303 expr = build_indirect_ref (expr, NULL); 304 return expr; 305 } 306 307 /* Do we need to check for a null pointer? */ 308 if (want_pointer && !nonnull) 309 { 310 /* If we know the conversion will not actually change the value 311 of EXPR, then we can avoid testing the expression for NULL. 312 We have to avoid generating a COMPONENT_REF for a base class 313 field, because other parts of the compiler know that such 314 expressions are always non-NULL. */ 315 if (!virtual_access && integer_zerop (offset)) 316 { 317 tree class_type; 318 /* TARGET_TYPE has been extracted from BINFO, and, is 319 therefore always cv-unqualified. Extract the 320 cv-qualifiers from EXPR so that the expression returned 321 matches the input. */ 322 class_type = TREE_TYPE (TREE_TYPE (expr)); 323 target_type 324 = cp_build_qualified_type (target_type, 325 cp_type_quals (class_type)); 326 return build_nop (build_pointer_type (target_type), expr); 327 } 328 null_test = error_mark_node; 329 } 330 331 /* Protect against multiple evaluation if necessary. */ 332 if (TREE_SIDE_EFFECTS (expr) && (null_test || virtual_access)) 333 expr = save_expr (expr); 334 335 /* Now that we've saved expr, build the real null test. */ 336 if (null_test) 337 { 338 tree zero = cp_convert (TREE_TYPE (expr), integer_zero_node); 339 null_test = fold_build2 (NE_EXPR, boolean_type_node, 340 expr, zero); 341 } 342 343 /* If this is a simple base reference, express it as a COMPONENT_REF. */ 344 if (code == PLUS_EXPR && !virtual_access 345 /* We don't build base fields for empty bases, and they aren't very 346 interesting to the optimizers anyway. */ 347 && !has_empty) 348 { 349 expr = build_indirect_ref (expr, NULL); 350 expr = build_simple_base_path (expr, binfo); 351 if (want_pointer) 352 expr = build_address (expr); 353 target_type = TREE_TYPE (expr); 354 goto out; 355 } 356 357 if (virtual_access) 358 { 359 /* Going via virtual base V_BINFO. We need the static offset 360 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to 361 V_BINFO. That offset is an entry in D_BINFO's vtable. */ 362 tree v_offset; 363 364 if (fixed_type_p < 0 && in_base_initializer) 365 { 366 /* In a base member initializer, we cannot rely on the 367 vtable being set up. We have to indirect via the 368 vtt_parm. */ 369 tree t; 370 371 t = TREE_TYPE (TYPE_VFIELD (current_class_type)); 372 t = build_pointer_type (t); 373 v_offset = convert (t, current_vtt_parm); 374 v_offset = build_indirect_ref (v_offset, NULL); 375 } 376 else 377 v_offset = build_vfield_ref (build_indirect_ref (expr, NULL), 378 TREE_TYPE (TREE_TYPE (expr))); 379 380 v_offset = build2 (PLUS_EXPR, TREE_TYPE (v_offset), 381 v_offset, BINFO_VPTR_FIELD (v_binfo)); 382 v_offset = build1 (NOP_EXPR, 383 build_pointer_type (ptrdiff_type_node), 384 v_offset); 385 v_offset = build_indirect_ref (v_offset, NULL); 386 TREE_CONSTANT (v_offset) = 1; 387 TREE_INVARIANT (v_offset) = 1; 388 389 offset = convert_to_integer (ptrdiff_type_node, 390 size_diffop (offset, 391 BINFO_OFFSET (v_binfo))); 392 393 if (!integer_zerop (offset)) 394 v_offset = build2 (code, ptrdiff_type_node, v_offset, offset); 395 396 if (fixed_type_p < 0) 397 /* Negative fixed_type_p means this is a constructor or destructor; 398 virtual base layout is fixed in in-charge [cd]tors, but not in 399 base [cd]tors. */ 400 offset = build3 (COND_EXPR, ptrdiff_type_node, 401 build2 (EQ_EXPR, boolean_type_node, 402 current_in_charge_parm, integer_zero_node), 403 v_offset, 404 convert_to_integer (ptrdiff_type_node, 405 BINFO_OFFSET (binfo))); 406 else 407 offset = v_offset; 408 } 409 410 target_type = cp_build_qualified_type 411 (target_type, cp_type_quals (TREE_TYPE (TREE_TYPE (expr)))); 412 ptr_target_type = build_pointer_type (target_type); 413 if (want_pointer) 414 target_type = ptr_target_type; 415 416 expr = build1 (NOP_EXPR, ptr_target_type, expr); 417 418 if (!integer_zerop (offset)) 419 expr = build2 (code, ptr_target_type, expr, offset); 420 else 421 null_test = NULL; 422 423 if (!want_pointer) 424 expr = build_indirect_ref (expr, NULL); 425 426 out: 427 if (null_test) 428 expr = fold_build3 (COND_EXPR, target_type, null_test, expr, 429 fold_build1 (NOP_EXPR, target_type, 430 integer_zero_node)); 431 432 return expr; 433} 434 435/* Subroutine of build_base_path; EXPR and BINFO are as in that function. 436 Perform a derived-to-base conversion by recursively building up a 437 sequence of COMPONENT_REFs to the appropriate base fields. */ 438 439static tree 440build_simple_base_path (tree expr, tree binfo) 441{ 442 tree type = BINFO_TYPE (binfo); 443 tree d_binfo = BINFO_INHERITANCE_CHAIN (binfo); 444 tree field; 445 446 if (d_binfo == NULL_TREE) 447 { 448 tree temp; 449 450 gcc_assert (TYPE_MAIN_VARIANT (TREE_TYPE (expr)) == type); 451 452 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x' 453 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only 454 an lvalue in the frontend; only _DECLs and _REFs are lvalues 455 in the backend. */ 456 temp = unary_complex_lvalue (ADDR_EXPR, expr); 457 if (temp) 458 expr = build_indirect_ref (temp, NULL); 459 460 return expr; 461 } 462 463 /* Recurse. */ 464 expr = build_simple_base_path (expr, d_binfo); 465 466 for (field = TYPE_FIELDS (BINFO_TYPE (d_binfo)); 467 field; field = TREE_CHAIN (field)) 468 /* Is this the base field created by build_base_field? */ 469 if (TREE_CODE (field) == FIELD_DECL 470 && DECL_FIELD_IS_BASE (field) 471 && TREE_TYPE (field) == type) 472 { 473 /* We don't use build_class_member_access_expr here, as that 474 has unnecessary checks, and more importantly results in 475 recursive calls to dfs_walk_once. */ 476 int type_quals = cp_type_quals (TREE_TYPE (expr)); 477 478 expr = build3 (COMPONENT_REF, 479 cp_build_qualified_type (type, type_quals), 480 expr, field, NULL_TREE); 481 expr = fold_if_not_in_template (expr); 482 483 /* Mark the expression const or volatile, as appropriate. 484 Even though we've dealt with the type above, we still have 485 to mark the expression itself. */ 486 if (type_quals & TYPE_QUAL_CONST) 487 TREE_READONLY (expr) = 1; 488 if (type_quals & TYPE_QUAL_VOLATILE) 489 TREE_THIS_VOLATILE (expr) = 1; 490 491 return expr; 492 } 493 494 /* Didn't find the base field?!? */ 495 gcc_unreachable (); 496} 497 498/* Convert OBJECT to the base TYPE. OBJECT is an expression whose 499 type is a class type or a pointer to a class type. In the former 500 case, TYPE is also a class type; in the latter it is another 501 pointer type. If CHECK_ACCESS is true, an error message is emitted 502 if TYPE is inaccessible. If OBJECT has pointer type, the value is 503 assumed to be non-NULL. */ 504 505tree 506convert_to_base (tree object, tree type, bool check_access, bool nonnull) 507{ 508 tree binfo; 509 tree object_type; 510 511 if (TYPE_PTR_P (TREE_TYPE (object))) 512 { 513 object_type = TREE_TYPE (TREE_TYPE (object)); 514 type = TREE_TYPE (type); 515 } 516 else 517 object_type = TREE_TYPE (object); 518 519 binfo = lookup_base (object_type, type, 520 check_access ? ba_check : ba_unique, 521 NULL); 522 if (!binfo || binfo == error_mark_node) 523 return error_mark_node; 524 525 return build_base_path (PLUS_EXPR, object, binfo, nonnull); 526} 527 528/* EXPR is an expression with unqualified class type. BASE is a base 529 binfo of that class type. Returns EXPR, converted to the BASE 530 type. This function assumes that EXPR is the most derived class; 531 therefore virtual bases can be found at their static offsets. */ 532 533tree 534convert_to_base_statically (tree expr, tree base) 535{ 536 tree expr_type; 537 538 expr_type = TREE_TYPE (expr); 539 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (base), expr_type)) 540 { 541 tree pointer_type; 542 543 pointer_type = build_pointer_type (expr_type); 544 expr = build_unary_op (ADDR_EXPR, expr, /*noconvert=*/1); 545 if (!integer_zerop (BINFO_OFFSET (base))) 546 expr = build2 (PLUS_EXPR, pointer_type, expr, 547 build_nop (pointer_type, BINFO_OFFSET (base))); 548 expr = build_nop (build_pointer_type (BINFO_TYPE (base)), expr); 549 expr = build1 (INDIRECT_REF, BINFO_TYPE (base), expr); 550 } 551 552 return expr; 553} 554 555 556tree 557build_vfield_ref (tree datum, tree type) 558{ 559 tree vfield, vcontext; 560 561 if (datum == error_mark_node) 562 return error_mark_node; 563 564 /* First, convert to the requested type. */ 565 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (datum), type)) 566 datum = convert_to_base (datum, type, /*check_access=*/false, 567 /*nonnull=*/true); 568 569 /* Second, the requested type may not be the owner of its own vptr. 570 If not, convert to the base class that owns it. We cannot use 571 convert_to_base here, because VCONTEXT may appear more than once 572 in the inheritance hierarchy of TYPE, and thus direct conversion 573 between the types may be ambiguous. Following the path back up 574 one step at a time via primary bases avoids the problem. */ 575 vfield = TYPE_VFIELD (type); 576 vcontext = DECL_CONTEXT (vfield); 577 while (!same_type_ignoring_top_level_qualifiers_p (vcontext, type)) 578 { 579 datum = build_simple_base_path (datum, CLASSTYPE_PRIMARY_BINFO (type)); 580 type = TREE_TYPE (datum); 581 } 582 583 return build3 (COMPONENT_REF, TREE_TYPE (vfield), datum, vfield, NULL_TREE); 584} 585 586/* Given an object INSTANCE, return an expression which yields the 587 vtable element corresponding to INDEX. There are many special 588 cases for INSTANCE which we take care of here, mainly to avoid 589 creating extra tree nodes when we don't have to. */ 590 591static tree 592build_vtbl_ref_1 (tree instance, tree idx) 593{ 594 tree aref; 595 tree vtbl = NULL_TREE; 596 597 /* Try to figure out what a reference refers to, and 598 access its virtual function table directly. */ 599 600 int cdtorp = 0; 601 tree fixed_type = fixed_type_or_null (instance, NULL, &cdtorp); 602 603 tree basetype = non_reference (TREE_TYPE (instance)); 604 605 if (fixed_type && !cdtorp) 606 { 607 tree binfo = lookup_base (fixed_type, basetype, 608 ba_unique | ba_quiet, NULL); 609 if (binfo) 610 vtbl = unshare_expr (BINFO_VTABLE (binfo)); 611 } 612 613 if (!vtbl) 614 vtbl = build_vfield_ref (instance, basetype); 615 616 assemble_external (vtbl); 617 618 aref = build_array_ref (vtbl, idx); 619 TREE_CONSTANT (aref) |= TREE_CONSTANT (vtbl) && TREE_CONSTANT (idx); 620 TREE_INVARIANT (aref) = TREE_CONSTANT (aref); 621 622 return aref; 623} 624 625tree 626build_vtbl_ref (tree instance, tree idx) 627{ 628 tree aref = build_vtbl_ref_1 (instance, idx); 629 630 return aref; 631} 632 633/* Given a stable object pointer INSTANCE_PTR, return an expression which 634 yields a function pointer corresponding to vtable element INDEX. */ 635 636tree 637build_vfn_ref (tree instance_ptr, tree idx) 638{ 639 tree aref; 640 641 aref = build_vtbl_ref_1 (build_indirect_ref (instance_ptr, 0), idx); 642 643 /* When using function descriptors, the address of the 644 vtable entry is treated as a function pointer. */ 645 if (TARGET_VTABLE_USES_DESCRIPTORS) 646 aref = build1 (NOP_EXPR, TREE_TYPE (aref), 647 build_unary_op (ADDR_EXPR, aref, /*noconvert=*/1)); 648 649 /* Remember this as a method reference, for later devirtualization. */ 650 aref = build3 (OBJ_TYPE_REF, TREE_TYPE (aref), aref, instance_ptr, idx); 651 652 return aref; 653} 654 655/* Return the name of the virtual function table (as an IDENTIFIER_NODE) 656 for the given TYPE. */ 657 658static tree 659get_vtable_name (tree type) 660{ 661 return mangle_vtbl_for_type (type); 662} 663 664/* Return an IDENTIFIER_NODE for the name of the virtual table table 665 for TYPE. */ 666 667tree 668get_vtt_name (tree type) 669{ 670 return mangle_vtt_for_type (type); 671} 672 673/* DECL is an entity associated with TYPE, like a virtual table or an 674 implicitly generated constructor. Determine whether or not DECL 675 should have external or internal linkage at the object file 676 level. This routine does not deal with COMDAT linkage and other 677 similar complexities; it simply sets TREE_PUBLIC if it possible for 678 entities in other translation units to contain copies of DECL, in 679 the abstract. */ 680 681void 682set_linkage_according_to_type (tree type, tree decl) 683{ 684 /* If TYPE involves a local class in a function with internal 685 linkage, then DECL should have internal linkage too. Other local 686 classes have no linkage -- but if their containing functions 687 have external linkage, it makes sense for DECL to have external 688 linkage too. That will allow template definitions to be merged, 689 for example. */ 690 if (no_linkage_check (type, /*relaxed_p=*/true)) 691 { 692 TREE_PUBLIC (decl) = 0; 693 DECL_INTERFACE_KNOWN (decl) = 1; 694 } 695 else 696 TREE_PUBLIC (decl) = 1; 697} 698 699/* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE. 700 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.) 701 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */ 702 703static tree 704build_vtable (tree class_type, tree name, tree vtable_type) 705{ 706 tree decl; 707 708 decl = build_lang_decl (VAR_DECL, name, vtable_type); 709 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME 710 now to avoid confusion in mangle_decl. */ 711 SET_DECL_ASSEMBLER_NAME (decl, name); 712 DECL_CONTEXT (decl) = class_type; 713 DECL_ARTIFICIAL (decl) = 1; 714 TREE_STATIC (decl) = 1; 715 TREE_READONLY (decl) = 1; 716 DECL_VIRTUAL_P (decl) = 1; 717 DECL_ALIGN (decl) = TARGET_VTABLE_ENTRY_ALIGN; 718 DECL_VTABLE_OR_VTT_P (decl) = 1; 719 /* At one time the vtable info was grabbed 2 words at a time. This 720 fails on sparc unless you have 8-byte alignment. (tiemann) */ 721 DECL_ALIGN (decl) = MAX (TYPE_ALIGN (double_type_node), 722 DECL_ALIGN (decl)); 723 set_linkage_according_to_type (class_type, decl); 724 /* The vtable has not been defined -- yet. */ 725 DECL_EXTERNAL (decl) = 1; 726 DECL_NOT_REALLY_EXTERN (decl) = 1; 727 728 /* Mark the VAR_DECL node representing the vtable itself as a 729 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It 730 is rather important that such things be ignored because any 731 effort to actually generate DWARF for them will run into 732 trouble when/if we encounter code like: 733 734 #pragma interface 735 struct S { virtual void member (); }; 736 737 because the artificial declaration of the vtable itself (as 738 manufactured by the g++ front end) will say that the vtable is 739 a static member of `S' but only *after* the debug output for 740 the definition of `S' has already been output. This causes 741 grief because the DWARF entry for the definition of the vtable 742 will try to refer back to an earlier *declaration* of the 743 vtable as a static member of `S' and there won't be one. We 744 might be able to arrange to have the "vtable static member" 745 attached to the member list for `S' before the debug info for 746 `S' get written (which would solve the problem) but that would 747 require more intrusive changes to the g++ front end. */ 748 DECL_IGNORED_P (decl) = 1; 749 750 return decl; 751} 752 753/* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic, 754 or even complete. If this does not exist, create it. If COMPLETE is 755 nonzero, then complete the definition of it -- that will render it 756 impossible to actually build the vtable, but is useful to get at those 757 which are known to exist in the runtime. */ 758 759tree 760get_vtable_decl (tree type, int complete) 761{ 762 tree decl; 763 764 if (CLASSTYPE_VTABLES (type)) 765 return CLASSTYPE_VTABLES (type); 766 767 decl = build_vtable (type, get_vtable_name (type), vtbl_type_node); 768 CLASSTYPE_VTABLES (type) = decl; 769 770 if (complete) 771 { 772 DECL_EXTERNAL (decl) = 1; 773 finish_decl (decl, NULL_TREE, NULL_TREE); 774 } 775 776 return decl; 777} 778 779/* Build the primary virtual function table for TYPE. If BINFO is 780 non-NULL, build the vtable starting with the initial approximation 781 that it is the same as the one which is the head of the association 782 list. Returns a nonzero value if a new vtable is actually 783 created. */ 784 785static int 786build_primary_vtable (tree binfo, tree type) 787{ 788 tree decl; 789 tree virtuals; 790 791 decl = get_vtable_decl (type, /*complete=*/0); 792 793 if (binfo) 794 { 795 if (BINFO_NEW_VTABLE_MARKED (binfo)) 796 /* We have already created a vtable for this base, so there's 797 no need to do it again. */ 798 return 0; 799 800 virtuals = copy_list (BINFO_VIRTUALS (binfo)); 801 TREE_TYPE (decl) = TREE_TYPE (get_vtbl_decl_for_binfo (binfo)); 802 DECL_SIZE (decl) = TYPE_SIZE (TREE_TYPE (decl)); 803 DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (TREE_TYPE (decl)); 804 } 805 else 806 { 807 gcc_assert (TREE_TYPE (decl) == vtbl_type_node); 808 virtuals = NULL_TREE; 809 } 810 811#ifdef GATHER_STATISTICS 812 n_vtables += 1; 813 n_vtable_elems += list_length (virtuals); 814#endif 815 816 /* Initialize the association list for this type, based 817 on our first approximation. */ 818 BINFO_VTABLE (TYPE_BINFO (type)) = decl; 819 BINFO_VIRTUALS (TYPE_BINFO (type)) = virtuals; 820 SET_BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (type)); 821 return 1; 822} 823 824/* Give BINFO a new virtual function table which is initialized 825 with a skeleton-copy of its original initialization. The only 826 entry that changes is the `delta' entry, so we can really 827 share a lot of structure. 828 829 FOR_TYPE is the most derived type which caused this table to 830 be needed. 831 832 Returns nonzero if we haven't met BINFO before. 833 834 The order in which vtables are built (by calling this function) for 835 an object must remain the same, otherwise a binary incompatibility 836 can result. */ 837 838static int 839build_secondary_vtable (tree binfo) 840{ 841 if (BINFO_NEW_VTABLE_MARKED (binfo)) 842 /* We already created a vtable for this base. There's no need to 843 do it again. */ 844 return 0; 845 846 /* Remember that we've created a vtable for this BINFO, so that we 847 don't try to do so again. */ 848 SET_BINFO_NEW_VTABLE_MARKED (binfo); 849 850 /* Make fresh virtual list, so we can smash it later. */ 851 BINFO_VIRTUALS (binfo) = copy_list (BINFO_VIRTUALS (binfo)); 852 853 /* Secondary vtables are laid out as part of the same structure as 854 the primary vtable. */ 855 BINFO_VTABLE (binfo) = NULL_TREE; 856 return 1; 857} 858 859/* Create a new vtable for BINFO which is the hierarchy dominated by 860 T. Return nonzero if we actually created a new vtable. */ 861 862static int 863make_new_vtable (tree t, tree binfo) 864{ 865 if (binfo == TYPE_BINFO (t)) 866 /* In this case, it is *type*'s vtable we are modifying. We start 867 with the approximation that its vtable is that of the 868 immediate base class. */ 869 return build_primary_vtable (binfo, t); 870 else 871 /* This is our very own copy of `basetype' to play with. Later, 872 we will fill in all the virtual functions that override the 873 virtual functions in these base classes which are not defined 874 by the current type. */ 875 return build_secondary_vtable (binfo); 876} 877 878/* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO 879 (which is in the hierarchy dominated by T) list FNDECL as its 880 BV_FN. DELTA is the required constant adjustment from the `this' 881 pointer where the vtable entry appears to the `this' required when 882 the function is actually called. */ 883 884static void 885modify_vtable_entry (tree t, 886 tree binfo, 887 tree fndecl, 888 tree delta, 889 tree *virtuals) 890{ 891 tree v; 892 893 v = *virtuals; 894 895 if (fndecl != BV_FN (v) 896 || !tree_int_cst_equal (delta, BV_DELTA (v))) 897 { 898 /* We need a new vtable for BINFO. */ 899 if (make_new_vtable (t, binfo)) 900 { 901 /* If we really did make a new vtable, we also made a copy 902 of the BINFO_VIRTUALS list. Now, we have to find the 903 corresponding entry in that list. */ 904 *virtuals = BINFO_VIRTUALS (binfo); 905 while (BV_FN (*virtuals) != BV_FN (v)) 906 *virtuals = TREE_CHAIN (*virtuals); 907 v = *virtuals; 908 } 909 910 BV_DELTA (v) = delta; 911 BV_VCALL_INDEX (v) = NULL_TREE; 912 BV_FN (v) = fndecl; 913 } 914} 915 916 917/* Add method METHOD to class TYPE. If USING_DECL is non-null, it is 918 the USING_DECL naming METHOD. Returns true if the method could be 919 added to the method vec. */ 920 921bool 922add_method (tree type, tree method, tree using_decl) 923{ 924 unsigned slot; 925 tree overload; 926 bool template_conv_p = false; 927 bool conv_p; 928 VEC(tree,gc) *method_vec; 929 bool complete_p; 930 bool insert_p = false; 931 tree current_fns; 932 933 if (method == error_mark_node) 934 return false; 935 936 complete_p = COMPLETE_TYPE_P (type); 937 conv_p = DECL_CONV_FN_P (method); 938 if (conv_p) 939 template_conv_p = (TREE_CODE (method) == TEMPLATE_DECL 940 && DECL_TEMPLATE_CONV_FN_P (method)); 941 942 method_vec = CLASSTYPE_METHOD_VEC (type); 943 if (!method_vec) 944 { 945 /* Make a new method vector. We start with 8 entries. We must 946 allocate at least two (for constructors and destructors), and 947 we're going to end up with an assignment operator at some 948 point as well. */ 949 method_vec = VEC_alloc (tree, gc, 8); 950 /* Create slots for constructors and destructors. */ 951 VEC_quick_push (tree, method_vec, NULL_TREE); 952 VEC_quick_push (tree, method_vec, NULL_TREE); 953 CLASSTYPE_METHOD_VEC (type) = method_vec; 954 } 955 956 /* Constructors and destructors go in special slots. */ 957 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (method)) 958 slot = CLASSTYPE_CONSTRUCTOR_SLOT; 959 else if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method)) 960 { 961 slot = CLASSTYPE_DESTRUCTOR_SLOT; 962 963 if (TYPE_FOR_JAVA (type)) 964 { 965 if (!DECL_ARTIFICIAL (method)) 966 error ("Java class %qT cannot have a destructor", type); 967 else if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 968 error ("Java class %qT cannot have an implicit non-trivial " 969 "destructor", 970 type); 971 } 972 } 973 else 974 { 975 tree m; 976 977 insert_p = true; 978 /* See if we already have an entry with this name. */ 979 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT; 980 VEC_iterate (tree, method_vec, slot, m); 981 ++slot) 982 { 983 m = OVL_CURRENT (m); 984 if (template_conv_p) 985 { 986 if (TREE_CODE (m) == TEMPLATE_DECL 987 && DECL_TEMPLATE_CONV_FN_P (m)) 988 insert_p = false; 989 break; 990 } 991 if (conv_p && !DECL_CONV_FN_P (m)) 992 break; 993 if (DECL_NAME (m) == DECL_NAME (method)) 994 { 995 insert_p = false; 996 break; 997 } 998 if (complete_p 999 && !DECL_CONV_FN_P (m) 1000 && DECL_NAME (m) > DECL_NAME (method)) 1001 break; 1002 } 1003 } 1004 current_fns = insert_p ? NULL_TREE : VEC_index (tree, method_vec, slot); 1005 1006 if (processing_template_decl) 1007 /* TYPE is a template class. Don't issue any errors now; wait 1008 until instantiation time to complain. */ 1009 ; 1010 else 1011 { 1012 tree fns; 1013 1014 /* Check to see if we've already got this method. */ 1015 for (fns = current_fns; fns; fns = OVL_NEXT (fns)) 1016 { 1017 tree fn = OVL_CURRENT (fns); 1018 tree fn_type; 1019 tree method_type; 1020 tree parms1; 1021 tree parms2; 1022 1023 if (TREE_CODE (fn) != TREE_CODE (method)) 1024 continue; 1025 1026 /* [over.load] Member function declarations with the 1027 same name and the same parameter types cannot be 1028 overloaded if any of them is a static member 1029 function declaration. 1030 1031 [namespace.udecl] When a using-declaration brings names 1032 from a base class into a derived class scope, member 1033 functions in the derived class override and/or hide member 1034 functions with the same name and parameter types in a base 1035 class (rather than conflicting). */ 1036 fn_type = TREE_TYPE (fn); 1037 method_type = TREE_TYPE (method); 1038 parms1 = TYPE_ARG_TYPES (fn_type); 1039 parms2 = TYPE_ARG_TYPES (method_type); 1040 1041 /* Compare the quals on the 'this' parm. Don't compare 1042 the whole types, as used functions are treated as 1043 coming from the using class in overload resolution. */ 1044 if (! DECL_STATIC_FUNCTION_P (fn) 1045 && ! DECL_STATIC_FUNCTION_P (method) 1046 && (TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms1))) 1047 != TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms2))))) 1048 continue; 1049 1050 /* For templates, the return type and template parameters 1051 must be identical. */ 1052 if (TREE_CODE (fn) == TEMPLATE_DECL 1053 && (!same_type_p (TREE_TYPE (fn_type), 1054 TREE_TYPE (method_type)) 1055 || !comp_template_parms (DECL_TEMPLATE_PARMS (fn), 1056 DECL_TEMPLATE_PARMS (method)))) 1057 continue; 1058 1059 if (! DECL_STATIC_FUNCTION_P (fn)) 1060 parms1 = TREE_CHAIN (parms1); 1061 if (! DECL_STATIC_FUNCTION_P (method)) 1062 parms2 = TREE_CHAIN (parms2); 1063 1064 if (compparms (parms1, parms2) 1065 && (!DECL_CONV_FN_P (fn) 1066 || same_type_p (TREE_TYPE (fn_type), 1067 TREE_TYPE (method_type)))) 1068 { 1069 if (using_decl) 1070 { 1071 if (DECL_CONTEXT (fn) == type) 1072 /* Defer to the local function. */ 1073 return false; 1074 if (DECL_CONTEXT (fn) == DECL_CONTEXT (method)) 1075 error ("repeated using declaration %q+D", using_decl); 1076 else 1077 error ("using declaration %q+D conflicts with a previous using declaration", 1078 using_decl); 1079 } 1080 else 1081 { 1082 error ("%q+#D cannot be overloaded", method); 1083 error ("with %q+#D", fn); 1084 } 1085 1086 /* We don't call duplicate_decls here to merge the 1087 declarations because that will confuse things if the 1088 methods have inline definitions. In particular, we 1089 will crash while processing the definitions. */ 1090 return false; 1091 } 1092 } 1093 } 1094 1095 /* A class should never have more than one destructor. */ 1096 if (current_fns && DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method)) 1097 return false; 1098 1099 /* Add the new binding. */ 1100 overload = build_overload (method, current_fns); 1101 1102 if (conv_p) 1103 TYPE_HAS_CONVERSION (type) = 1; 1104 else if (slot >= CLASSTYPE_FIRST_CONVERSION_SLOT && !complete_p) 1105 push_class_level_binding (DECL_NAME (method), overload); 1106 1107 if (insert_p) 1108 { 1109 /* We only expect to add few methods in the COMPLETE_P case, so 1110 just make room for one more method in that case. */ 1111 if (VEC_reserve (tree, gc, method_vec, complete_p ? -1 : 1)) 1112 CLASSTYPE_METHOD_VEC (type) = method_vec; 1113 if (slot == VEC_length (tree, method_vec)) 1114 VEC_quick_push (tree, method_vec, overload); 1115 else 1116 VEC_quick_insert (tree, method_vec, slot, overload); 1117 } 1118 else 1119 /* Replace the current slot. */ 1120 VEC_replace (tree, method_vec, slot, overload); 1121 return true; 1122} 1123 1124/* Subroutines of finish_struct. */ 1125 1126/* Change the access of FDECL to ACCESS in T. Return 1 if change was 1127 legit, otherwise return 0. */ 1128 1129static int 1130alter_access (tree t, tree fdecl, tree access) 1131{ 1132 tree elem; 1133 1134 if (!DECL_LANG_SPECIFIC (fdecl)) 1135 retrofit_lang_decl (fdecl); 1136 1137 gcc_assert (!DECL_DISCRIMINATOR_P (fdecl)); 1138 1139 elem = purpose_member (t, DECL_ACCESS (fdecl)); 1140 if (elem) 1141 { 1142 if (TREE_VALUE (elem) != access) 1143 { 1144 if (TREE_CODE (TREE_TYPE (fdecl)) == FUNCTION_DECL) 1145 error ("conflicting access specifications for method" 1146 " %q+D, ignored", TREE_TYPE (fdecl)); 1147 else 1148 error ("conflicting access specifications for field %qE, ignored", 1149 DECL_NAME (fdecl)); 1150 } 1151 else 1152 { 1153 /* They're changing the access to the same thing they changed 1154 it to before. That's OK. */ 1155 ; 1156 } 1157 } 1158 else 1159 { 1160 perform_or_defer_access_check (TYPE_BINFO (t), fdecl); 1161 DECL_ACCESS (fdecl) = tree_cons (t, access, DECL_ACCESS (fdecl)); 1162 return 1; 1163 } 1164 return 0; 1165} 1166 1167/* Process the USING_DECL, which is a member of T. */ 1168 1169static void 1170handle_using_decl (tree using_decl, tree t) 1171{ 1172 tree decl = USING_DECL_DECLS (using_decl); 1173 tree name = DECL_NAME (using_decl); 1174 tree access 1175 = TREE_PRIVATE (using_decl) ? access_private_node 1176 : TREE_PROTECTED (using_decl) ? access_protected_node 1177 : access_public_node; 1178 tree flist = NULL_TREE; 1179 tree old_value; 1180 1181 gcc_assert (!processing_template_decl && decl); 1182 1183 old_value = lookup_member (t, name, /*protect=*/0, /*want_type=*/false); 1184 if (old_value) 1185 { 1186 if (is_overloaded_fn (old_value)) 1187 old_value = OVL_CURRENT (old_value); 1188 1189 if (DECL_P (old_value) && DECL_CONTEXT (old_value) == t) 1190 /* OK */; 1191 else 1192 old_value = NULL_TREE; 1193 } 1194 1195 cp_emit_debug_info_for_using (decl, USING_DECL_SCOPE (using_decl)); 1196 1197 if (is_overloaded_fn (decl)) 1198 flist = decl; 1199 1200 if (! old_value) 1201 ; 1202 else if (is_overloaded_fn (old_value)) 1203 { 1204 if (flist) 1205 /* It's OK to use functions from a base when there are functions with 1206 the same name already present in the current class. */; 1207 else 1208 { 1209 error ("%q+D invalid in %q#T", using_decl, t); 1210 error (" because of local method %q+#D with same name", 1211 OVL_CURRENT (old_value)); 1212 return; 1213 } 1214 } 1215 else if (!DECL_ARTIFICIAL (old_value)) 1216 { 1217 error ("%q+D invalid in %q#T", using_decl, t); 1218 error (" because of local member %q+#D with same name", old_value); 1219 return; 1220 } 1221 1222 /* Make type T see field decl FDECL with access ACCESS. */ 1223 if (flist) 1224 for (; flist; flist = OVL_NEXT (flist)) 1225 { 1226 add_method (t, OVL_CURRENT (flist), using_decl); 1227 alter_access (t, OVL_CURRENT (flist), access); 1228 } 1229 else 1230 alter_access (t, decl, access); 1231} 1232 1233/* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P, 1234 and NO_CONST_ASN_REF_P. Also set flag bits in T based on 1235 properties of the bases. */ 1236 1237static void 1238check_bases (tree t, 1239 int* cant_have_const_ctor_p, 1240 int* no_const_asn_ref_p) 1241{ 1242 int i; 1243 int seen_non_virtual_nearly_empty_base_p; 1244 tree base_binfo; 1245 tree binfo; 1246 1247 seen_non_virtual_nearly_empty_base_p = 0; 1248 1249 for (binfo = TYPE_BINFO (t), i = 0; 1250 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 1251 { 1252 tree basetype = TREE_TYPE (base_binfo); 1253 1254 gcc_assert (COMPLETE_TYPE_P (basetype)); 1255 1256 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P 1257 here because the case of virtual functions but non-virtual 1258 dtor is handled in finish_struct_1. */ 1259 if (warn_ecpp && ! TYPE_POLYMORPHIC_P (basetype)) 1260 warning (0, "base class %q#T has a non-virtual destructor", basetype); 1261 1262 /* If the base class doesn't have copy constructors or 1263 assignment operators that take const references, then the 1264 derived class cannot have such a member automatically 1265 generated. */ 1266 if (! TYPE_HAS_CONST_INIT_REF (basetype)) 1267 *cant_have_const_ctor_p = 1; 1268 if (TYPE_HAS_ASSIGN_REF (basetype) 1269 && !TYPE_HAS_CONST_ASSIGN_REF (basetype)) 1270 *no_const_asn_ref_p = 1; 1271 1272 if (BINFO_VIRTUAL_P (base_binfo)) 1273 /* A virtual base does not effect nearly emptiness. */ 1274 ; 1275 else if (CLASSTYPE_NEARLY_EMPTY_P (basetype)) 1276 { 1277 if (seen_non_virtual_nearly_empty_base_p) 1278 /* And if there is more than one nearly empty base, then the 1279 derived class is not nearly empty either. */ 1280 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 1281 else 1282 /* Remember we've seen one. */ 1283 seen_non_virtual_nearly_empty_base_p = 1; 1284 } 1285 else if (!is_empty_class (basetype)) 1286 /* If the base class is not empty or nearly empty, then this 1287 class cannot be nearly empty. */ 1288 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 1289 1290 /* A lot of properties from the bases also apply to the derived 1291 class. */ 1292 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (basetype); 1293 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) 1294 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (basetype); 1295 TYPE_HAS_COMPLEX_ASSIGN_REF (t) 1296 |= TYPE_HAS_COMPLEX_ASSIGN_REF (basetype); 1297 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (basetype); 1298 TYPE_POLYMORPHIC_P (t) |= TYPE_POLYMORPHIC_P (basetype); 1299 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) 1300 |= CLASSTYPE_CONTAINS_EMPTY_CLASS_P (basetype); 1301 } 1302} 1303 1304/* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for 1305 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those 1306 that have had a nearly-empty virtual primary base stolen by some 1307 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for 1308 T. */ 1309 1310static void 1311determine_primary_bases (tree t) 1312{ 1313 unsigned i; 1314 tree primary = NULL_TREE; 1315 tree type_binfo = TYPE_BINFO (t); 1316 tree base_binfo; 1317 1318 /* Determine the primary bases of our bases. */ 1319 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo; 1320 base_binfo = TREE_CHAIN (base_binfo)) 1321 { 1322 tree primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (base_binfo)); 1323 1324 /* See if we're the non-virtual primary of our inheritance 1325 chain. */ 1326 if (!BINFO_VIRTUAL_P (base_binfo)) 1327 { 1328 tree parent = BINFO_INHERITANCE_CHAIN (base_binfo); 1329 tree parent_primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (parent)); 1330 1331 if (parent_primary 1332 && SAME_BINFO_TYPE_P (BINFO_TYPE (base_binfo), 1333 BINFO_TYPE (parent_primary))) 1334 /* We are the primary binfo. */ 1335 BINFO_PRIMARY_P (base_binfo) = 1; 1336 } 1337 /* Determine if we have a virtual primary base, and mark it so. 1338 */ 1339 if (primary && BINFO_VIRTUAL_P (primary)) 1340 { 1341 tree this_primary = copied_binfo (primary, base_binfo); 1342 1343 if (BINFO_PRIMARY_P (this_primary)) 1344 /* Someone already claimed this base. */ 1345 BINFO_LOST_PRIMARY_P (base_binfo) = 1; 1346 else 1347 { 1348 tree delta; 1349 1350 BINFO_PRIMARY_P (this_primary) = 1; 1351 BINFO_INHERITANCE_CHAIN (this_primary) = base_binfo; 1352 1353 /* A virtual binfo might have been copied from within 1354 another hierarchy. As we're about to use it as a 1355 primary base, make sure the offsets match. */ 1356 delta = size_diffop (convert (ssizetype, 1357 BINFO_OFFSET (base_binfo)), 1358 convert (ssizetype, 1359 BINFO_OFFSET (this_primary))); 1360 1361 propagate_binfo_offsets (this_primary, delta); 1362 } 1363 } 1364 } 1365 1366 /* First look for a dynamic direct non-virtual base. */ 1367 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, base_binfo); i++) 1368 { 1369 tree basetype = BINFO_TYPE (base_binfo); 1370 1371 if (TYPE_CONTAINS_VPTR_P (basetype) && !BINFO_VIRTUAL_P (base_binfo)) 1372 { 1373 primary = base_binfo; 1374 goto found; 1375 } 1376 } 1377 1378 /* A "nearly-empty" virtual base class can be the primary base 1379 class, if no non-virtual polymorphic base can be found. Look for 1380 a nearly-empty virtual dynamic base that is not already a primary 1381 base of something in the hierarchy. If there is no such base, 1382 just pick the first nearly-empty virtual base. */ 1383 1384 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo; 1385 base_binfo = TREE_CHAIN (base_binfo)) 1386 if (BINFO_VIRTUAL_P (base_binfo) 1387 && CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (base_binfo))) 1388 { 1389 if (!BINFO_PRIMARY_P (base_binfo)) 1390 { 1391 /* Found one that is not primary. */ 1392 primary = base_binfo; 1393 goto found; 1394 } 1395 else if (!primary) 1396 /* Remember the first candidate. */ 1397 primary = base_binfo; 1398 } 1399 1400 found: 1401 /* If we've got a primary base, use it. */ 1402 if (primary) 1403 { 1404 tree basetype = BINFO_TYPE (primary); 1405 1406 CLASSTYPE_PRIMARY_BINFO (t) = primary; 1407 if (BINFO_PRIMARY_P (primary)) 1408 /* We are stealing a primary base. */ 1409 BINFO_LOST_PRIMARY_P (BINFO_INHERITANCE_CHAIN (primary)) = 1; 1410 BINFO_PRIMARY_P (primary) = 1; 1411 if (BINFO_VIRTUAL_P (primary)) 1412 { 1413 tree delta; 1414 1415 BINFO_INHERITANCE_CHAIN (primary) = type_binfo; 1416 /* A virtual binfo might have been copied from within 1417 another hierarchy. As we're about to use it as a primary 1418 base, make sure the offsets match. */ 1419 delta = size_diffop (ssize_int (0), 1420 convert (ssizetype, BINFO_OFFSET (primary))); 1421 1422 propagate_binfo_offsets (primary, delta); 1423 } 1424 1425 primary = TYPE_BINFO (basetype); 1426 1427 TYPE_VFIELD (t) = TYPE_VFIELD (basetype); 1428 BINFO_VTABLE (type_binfo) = BINFO_VTABLE (primary); 1429 BINFO_VIRTUALS (type_binfo) = BINFO_VIRTUALS (primary); 1430 } 1431} 1432 1433/* Set memoizing fields and bits of T (and its variants) for later 1434 use. */ 1435 1436static void 1437finish_struct_bits (tree t) 1438{ 1439 tree variants; 1440 1441 /* Fix up variants (if any). */ 1442 for (variants = TYPE_NEXT_VARIANT (t); 1443 variants; 1444 variants = TYPE_NEXT_VARIANT (variants)) 1445 { 1446 /* These fields are in the _TYPE part of the node, not in 1447 the TYPE_LANG_SPECIFIC component, so they are not shared. */ 1448 TYPE_HAS_CONSTRUCTOR (variants) = TYPE_HAS_CONSTRUCTOR (t); 1449 TYPE_NEEDS_CONSTRUCTING (variants) = TYPE_NEEDS_CONSTRUCTING (t); 1450 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (variants) 1451 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t); 1452 1453 TYPE_POLYMORPHIC_P (variants) = TYPE_POLYMORPHIC_P (t); 1454 1455 TYPE_BINFO (variants) = TYPE_BINFO (t); 1456 1457 /* Copy whatever these are holding today. */ 1458 TYPE_VFIELD (variants) = TYPE_VFIELD (t); 1459 TYPE_METHODS (variants) = TYPE_METHODS (t); 1460 TYPE_FIELDS (variants) = TYPE_FIELDS (t); 1461 TYPE_SIZE (variants) = TYPE_SIZE (t); 1462 TYPE_SIZE_UNIT (variants) = TYPE_SIZE_UNIT (t); 1463 } 1464 1465 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) && TYPE_POLYMORPHIC_P (t)) 1466 /* For a class w/o baseclasses, 'finish_struct' has set 1467 CLASSTYPE_PURE_VIRTUALS correctly (by definition). 1468 Similarly for a class whose base classes do not have vtables. 1469 When neither of these is true, we might have removed abstract 1470 virtuals (by providing a definition), added some (by declaring 1471 new ones), or redeclared ones from a base class. We need to 1472 recalculate what's really an abstract virtual at this point (by 1473 looking in the vtables). */ 1474 get_pure_virtuals (t); 1475 1476 /* If this type has a copy constructor or a destructor, force its 1477 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be 1478 nonzero. This will cause it to be passed by invisible reference 1479 and prevent it from being returned in a register. */ 1480 if (! TYPE_HAS_TRIVIAL_INIT_REF (t) || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)) 1481 { 1482 tree variants; 1483 DECL_MODE (TYPE_MAIN_DECL (t)) = BLKmode; 1484 for (variants = t; variants; variants = TYPE_NEXT_VARIANT (variants)) 1485 { 1486 TYPE_MODE (variants) = BLKmode; 1487 TREE_ADDRESSABLE (variants) = 1; 1488 } 1489 } 1490} 1491 1492/* Issue warnings about T having private constructors, but no friends, 1493 and so forth. 1494 1495 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or 1496 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any 1497 non-private static member functions. */ 1498 1499static void 1500maybe_warn_about_overly_private_class (tree t) 1501{ 1502 int has_member_fn = 0; 1503 int has_nonprivate_method = 0; 1504 tree fn; 1505 1506 if (!warn_ctor_dtor_privacy 1507 /* If the class has friends, those entities might create and 1508 access instances, so we should not warn. */ 1509 || (CLASSTYPE_FRIEND_CLASSES (t) 1510 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t))) 1511 /* We will have warned when the template was declared; there's 1512 no need to warn on every instantiation. */ 1513 || CLASSTYPE_TEMPLATE_INSTANTIATION (t)) 1514 /* There's no reason to even consider warning about this 1515 class. */ 1516 return; 1517 1518 /* We only issue one warning, if more than one applies, because 1519 otherwise, on code like: 1520 1521 class A { 1522 // Oops - forgot `public:' 1523 A(); 1524 A(const A&); 1525 ~A(); 1526 }; 1527 1528 we warn several times about essentially the same problem. */ 1529 1530 /* Check to see if all (non-constructor, non-destructor) member 1531 functions are private. (Since there are no friends or 1532 non-private statics, we can't ever call any of the private member 1533 functions.) */ 1534 for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn)) 1535 /* We're not interested in compiler-generated methods; they don't 1536 provide any way to call private members. */ 1537 if (!DECL_ARTIFICIAL (fn)) 1538 { 1539 if (!TREE_PRIVATE (fn)) 1540 { 1541 if (DECL_STATIC_FUNCTION_P (fn)) 1542 /* A non-private static member function is just like a 1543 friend; it can create and invoke private member 1544 functions, and be accessed without a class 1545 instance. */ 1546 return; 1547 1548 has_nonprivate_method = 1; 1549 /* Keep searching for a static member function. */ 1550 } 1551 else if (!DECL_CONSTRUCTOR_P (fn) && !DECL_DESTRUCTOR_P (fn)) 1552 has_member_fn = 1; 1553 } 1554 1555 if (!has_nonprivate_method && has_member_fn) 1556 { 1557 /* There are no non-private methods, and there's at least one 1558 private member function that isn't a constructor or 1559 destructor. (If all the private members are 1560 constructors/destructors we want to use the code below that 1561 issues error messages specifically referring to 1562 constructors/destructors.) */ 1563 unsigned i; 1564 tree binfo = TYPE_BINFO (t); 1565 1566 for (i = 0; i != BINFO_N_BASE_BINFOS (binfo); i++) 1567 if (BINFO_BASE_ACCESS (binfo, i) != access_private_node) 1568 { 1569 has_nonprivate_method = 1; 1570 break; 1571 } 1572 if (!has_nonprivate_method) 1573 { 1574 warning (0, "all member functions in class %qT are private", t); 1575 return; 1576 } 1577 } 1578 1579 /* Even if some of the member functions are non-private, the class 1580 won't be useful for much if all the constructors or destructors 1581 are private: such an object can never be created or destroyed. */ 1582 fn = CLASSTYPE_DESTRUCTORS (t); 1583 if (fn && TREE_PRIVATE (fn)) 1584 { 1585 warning (0, "%q#T only defines a private destructor and has no friends", 1586 t); 1587 return; 1588 } 1589 1590 if (TYPE_HAS_CONSTRUCTOR (t) 1591 /* Implicitly generated constructors are always public. */ 1592 && (!CLASSTYPE_LAZY_DEFAULT_CTOR (t) 1593 || !CLASSTYPE_LAZY_COPY_CTOR (t))) 1594 { 1595 int nonprivate_ctor = 0; 1596 1597 /* If a non-template class does not define a copy 1598 constructor, one is defined for it, enabling it to avoid 1599 this warning. For a template class, this does not 1600 happen, and so we would normally get a warning on: 1601 1602 template <class T> class C { private: C(); }; 1603 1604 To avoid this asymmetry, we check TYPE_HAS_INIT_REF. All 1605 complete non-template or fully instantiated classes have this 1606 flag set. */ 1607 if (!TYPE_HAS_INIT_REF (t)) 1608 nonprivate_ctor = 1; 1609 else 1610 for (fn = CLASSTYPE_CONSTRUCTORS (t); fn; fn = OVL_NEXT (fn)) 1611 { 1612 tree ctor = OVL_CURRENT (fn); 1613 /* Ideally, we wouldn't count copy constructors (or, in 1614 fact, any constructor that takes an argument of the 1615 class type as a parameter) because such things cannot 1616 be used to construct an instance of the class unless 1617 you already have one. But, for now at least, we're 1618 more generous. */ 1619 if (! TREE_PRIVATE (ctor)) 1620 { 1621 nonprivate_ctor = 1; 1622 break; 1623 } 1624 } 1625 1626 if (nonprivate_ctor == 0) 1627 { 1628 warning (0, "%q#T only defines private constructors and has no friends", 1629 t); 1630 return; 1631 } 1632 } 1633} 1634 1635static struct { 1636 gt_pointer_operator new_value; 1637 void *cookie; 1638} resort_data; 1639 1640/* Comparison function to compare two TYPE_METHOD_VEC entries by name. */ 1641 1642static int 1643method_name_cmp (const void* m1_p, const void* m2_p) 1644{ 1645 const tree *const m1 = m1_p; 1646 const tree *const m2 = m2_p; 1647 1648 if (*m1 == NULL_TREE && *m2 == NULL_TREE) 1649 return 0; 1650 if (*m1 == NULL_TREE) 1651 return -1; 1652 if (*m2 == NULL_TREE) 1653 return 1; 1654 if (DECL_NAME (OVL_CURRENT (*m1)) < DECL_NAME (OVL_CURRENT (*m2))) 1655 return -1; 1656 return 1; 1657} 1658 1659/* This routine compares two fields like method_name_cmp but using the 1660 pointer operator in resort_field_decl_data. */ 1661 1662static int 1663resort_method_name_cmp (const void* m1_p, const void* m2_p) 1664{ 1665 const tree *const m1 = m1_p; 1666 const tree *const m2 = m2_p; 1667 if (*m1 == NULL_TREE && *m2 == NULL_TREE) 1668 return 0; 1669 if (*m1 == NULL_TREE) 1670 return -1; 1671 if (*m2 == NULL_TREE) 1672 return 1; 1673 { 1674 tree d1 = DECL_NAME (OVL_CURRENT (*m1)); 1675 tree d2 = DECL_NAME (OVL_CURRENT (*m2)); 1676 resort_data.new_value (&d1, resort_data.cookie); 1677 resort_data.new_value (&d2, resort_data.cookie); 1678 if (d1 < d2) 1679 return -1; 1680 } 1681 return 1; 1682} 1683 1684/* Resort TYPE_METHOD_VEC because pointers have been reordered. */ 1685 1686void 1687resort_type_method_vec (void* obj, 1688 void* orig_obj ATTRIBUTE_UNUSED , 1689 gt_pointer_operator new_value, 1690 void* cookie) 1691{ 1692 VEC(tree,gc) *method_vec = (VEC(tree,gc) *) obj; 1693 int len = VEC_length (tree, method_vec); 1694 size_t slot; 1695 tree fn; 1696 1697 /* The type conversion ops have to live at the front of the vec, so we 1698 can't sort them. */ 1699 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT; 1700 VEC_iterate (tree, method_vec, slot, fn); 1701 ++slot) 1702 if (!DECL_CONV_FN_P (OVL_CURRENT (fn))) 1703 break; 1704 1705 if (len - slot > 1) 1706 { 1707 resort_data.new_value = new_value; 1708 resort_data.cookie = cookie; 1709 qsort (VEC_address (tree, method_vec) + slot, len - slot, sizeof (tree), 1710 resort_method_name_cmp); 1711 } 1712} 1713 1714/* Warn about duplicate methods in fn_fields. 1715 1716 Sort methods that are not special (i.e., constructors, destructors, 1717 and type conversion operators) so that we can find them faster in 1718 search. */ 1719 1720static void 1721finish_struct_methods (tree t) 1722{ 1723 tree fn_fields; 1724 VEC(tree,gc) *method_vec; 1725 int slot, len; 1726 1727 method_vec = CLASSTYPE_METHOD_VEC (t); 1728 if (!method_vec) 1729 return; 1730 1731 len = VEC_length (tree, method_vec); 1732 1733 /* Clear DECL_IN_AGGR_P for all functions. */ 1734 for (fn_fields = TYPE_METHODS (t); fn_fields; 1735 fn_fields = TREE_CHAIN (fn_fields)) 1736 DECL_IN_AGGR_P (fn_fields) = 0; 1737 1738 /* Issue warnings about private constructors and such. If there are 1739 no methods, then some public defaults are generated. */ 1740 maybe_warn_about_overly_private_class (t); 1741 1742 /* The type conversion ops have to live at the front of the vec, so we 1743 can't sort them. */ 1744 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT; 1745 VEC_iterate (tree, method_vec, slot, fn_fields); 1746 ++slot) 1747 if (!DECL_CONV_FN_P (OVL_CURRENT (fn_fields))) 1748 break; 1749 if (len - slot > 1) 1750 qsort (VEC_address (tree, method_vec) + slot, 1751 len-slot, sizeof (tree), method_name_cmp); 1752} 1753 1754/* Make BINFO's vtable have N entries, including RTTI entries, 1755 vbase and vcall offsets, etc. Set its type and call the backend 1756 to lay it out. */ 1757 1758static void 1759layout_vtable_decl (tree binfo, int n) 1760{ 1761 tree atype; 1762 tree vtable; 1763 1764 atype = build_cplus_array_type (vtable_entry_type, 1765 build_index_type (size_int (n - 1))); 1766 layout_type (atype); 1767 1768 /* We may have to grow the vtable. */ 1769 vtable = get_vtbl_decl_for_binfo (binfo); 1770 if (!same_type_p (TREE_TYPE (vtable), atype)) 1771 { 1772 TREE_TYPE (vtable) = atype; 1773 DECL_SIZE (vtable) = DECL_SIZE_UNIT (vtable) = NULL_TREE; 1774 layout_decl (vtable, 0); 1775 } 1776} 1777 1778/* True iff FNDECL and BASE_FNDECL (both non-static member functions) 1779 have the same signature. */ 1780 1781int 1782same_signature_p (tree fndecl, tree base_fndecl) 1783{ 1784 /* One destructor overrides another if they are the same kind of 1785 destructor. */ 1786 if (DECL_DESTRUCTOR_P (base_fndecl) && DECL_DESTRUCTOR_P (fndecl) 1787 && special_function_p (base_fndecl) == special_function_p (fndecl)) 1788 return 1; 1789 /* But a non-destructor never overrides a destructor, nor vice 1790 versa, nor do different kinds of destructors override 1791 one-another. For example, a complete object destructor does not 1792 override a deleting destructor. */ 1793 if (DECL_DESTRUCTOR_P (base_fndecl) || DECL_DESTRUCTOR_P (fndecl)) 1794 return 0; 1795 1796 if (DECL_NAME (fndecl) == DECL_NAME (base_fndecl) 1797 || (DECL_CONV_FN_P (fndecl) 1798 && DECL_CONV_FN_P (base_fndecl) 1799 && same_type_p (DECL_CONV_FN_TYPE (fndecl), 1800 DECL_CONV_FN_TYPE (base_fndecl)))) 1801 { 1802 tree types, base_types; 1803 types = TYPE_ARG_TYPES (TREE_TYPE (fndecl)); 1804 base_types = TYPE_ARG_TYPES (TREE_TYPE (base_fndecl)); 1805 if ((TYPE_QUALS (TREE_TYPE (TREE_VALUE (base_types))) 1806 == TYPE_QUALS (TREE_TYPE (TREE_VALUE (types)))) 1807 && compparms (TREE_CHAIN (base_types), TREE_CHAIN (types))) 1808 return 1; 1809 } 1810 return 0; 1811} 1812 1813/* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a 1814 subobject. */ 1815 1816static bool 1817base_derived_from (tree derived, tree base) 1818{ 1819 tree probe; 1820 1821 for (probe = base; probe; probe = BINFO_INHERITANCE_CHAIN (probe)) 1822 { 1823 if (probe == derived) 1824 return true; 1825 else if (BINFO_VIRTUAL_P (probe)) 1826 /* If we meet a virtual base, we can't follow the inheritance 1827 any more. See if the complete type of DERIVED contains 1828 such a virtual base. */ 1829 return (binfo_for_vbase (BINFO_TYPE (probe), BINFO_TYPE (derived)) 1830 != NULL_TREE); 1831 } 1832 return false; 1833} 1834 1835typedef struct find_final_overrider_data_s { 1836 /* The function for which we are trying to find a final overrider. */ 1837 tree fn; 1838 /* The base class in which the function was declared. */ 1839 tree declaring_base; 1840 /* The candidate overriders. */ 1841 tree candidates; 1842 /* Path to most derived. */ 1843 VEC(tree,heap) *path; 1844} find_final_overrider_data; 1845 1846/* Add the overrider along the current path to FFOD->CANDIDATES. 1847 Returns true if an overrider was found; false otherwise. */ 1848 1849static bool 1850dfs_find_final_overrider_1 (tree binfo, 1851 find_final_overrider_data *ffod, 1852 unsigned depth) 1853{ 1854 tree method; 1855 1856 /* If BINFO is not the most derived type, try a more derived class. 1857 A definition there will overrider a definition here. */ 1858 if (depth) 1859 { 1860 depth--; 1861 if (dfs_find_final_overrider_1 1862 (VEC_index (tree, ffod->path, depth), ffod, depth)) 1863 return true; 1864 } 1865 1866 method = look_for_overrides_here (BINFO_TYPE (binfo), ffod->fn); 1867 if (method) 1868 { 1869 tree *candidate = &ffod->candidates; 1870 1871 /* Remove any candidates overridden by this new function. */ 1872 while (*candidate) 1873 { 1874 /* If *CANDIDATE overrides METHOD, then METHOD 1875 cannot override anything else on the list. */ 1876 if (base_derived_from (TREE_VALUE (*candidate), binfo)) 1877 return true; 1878 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */ 1879 if (base_derived_from (binfo, TREE_VALUE (*candidate))) 1880 *candidate = TREE_CHAIN (*candidate); 1881 else 1882 candidate = &TREE_CHAIN (*candidate); 1883 } 1884 1885 /* Add the new function. */ 1886 ffod->candidates = tree_cons (method, binfo, ffod->candidates); 1887 return true; 1888 } 1889 1890 return false; 1891} 1892 1893/* Called from find_final_overrider via dfs_walk. */ 1894 1895static tree 1896dfs_find_final_overrider_pre (tree binfo, void *data) 1897{ 1898 find_final_overrider_data *ffod = (find_final_overrider_data *) data; 1899 1900 if (binfo == ffod->declaring_base) 1901 dfs_find_final_overrider_1 (binfo, ffod, VEC_length (tree, ffod->path)); 1902 VEC_safe_push (tree, heap, ffod->path, binfo); 1903 1904 return NULL_TREE; 1905} 1906 1907static tree 1908dfs_find_final_overrider_post (tree binfo ATTRIBUTE_UNUSED, void *data) 1909{ 1910 find_final_overrider_data *ffod = (find_final_overrider_data *) data; 1911 VEC_pop (tree, ffod->path); 1912 1913 return NULL_TREE; 1914} 1915 1916/* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for 1917 FN and whose TREE_VALUE is the binfo for the base where the 1918 overriding occurs. BINFO (in the hierarchy dominated by the binfo 1919 DERIVED) is the base object in which FN is declared. */ 1920 1921static tree 1922find_final_overrider (tree derived, tree binfo, tree fn) 1923{ 1924 find_final_overrider_data ffod; 1925 1926 /* Getting this right is a little tricky. This is valid: 1927 1928 struct S { virtual void f (); }; 1929 struct T { virtual void f (); }; 1930 struct U : public S, public T { }; 1931 1932 even though calling `f' in `U' is ambiguous. But, 1933 1934 struct R { virtual void f(); }; 1935 struct S : virtual public R { virtual void f (); }; 1936 struct T : virtual public R { virtual void f (); }; 1937 struct U : public S, public T { }; 1938 1939 is not -- there's no way to decide whether to put `S::f' or 1940 `T::f' in the vtable for `R'. 1941 1942 The solution is to look at all paths to BINFO. If we find 1943 different overriders along any two, then there is a problem. */ 1944 if (DECL_THUNK_P (fn)) 1945 fn = THUNK_TARGET (fn); 1946 1947 /* Determine the depth of the hierarchy. */ 1948 ffod.fn = fn; 1949 ffod.declaring_base = binfo; 1950 ffod.candidates = NULL_TREE; 1951 ffod.path = VEC_alloc (tree, heap, 30); 1952 1953 dfs_walk_all (derived, dfs_find_final_overrider_pre, 1954 dfs_find_final_overrider_post, &ffod); 1955 1956 VEC_free (tree, heap, ffod.path); 1957 1958 /* If there was no winner, issue an error message. */ 1959 if (!ffod.candidates || TREE_CHAIN (ffod.candidates)) 1960 return error_mark_node; 1961 1962 return ffod.candidates; 1963} 1964 1965/* Return the index of the vcall offset for FN when TYPE is used as a 1966 virtual base. */ 1967 1968static tree 1969get_vcall_index (tree fn, tree type) 1970{ 1971 VEC(tree_pair_s,gc) *indices = CLASSTYPE_VCALL_INDICES (type); 1972 tree_pair_p p; 1973 unsigned ix; 1974 1975 for (ix = 0; VEC_iterate (tree_pair_s, indices, ix, p); ix++) 1976 if ((DECL_DESTRUCTOR_P (fn) && DECL_DESTRUCTOR_P (p->purpose)) 1977 || same_signature_p (fn, p->purpose)) 1978 return p->value; 1979 1980 /* There should always be an appropriate index. */ 1981 gcc_unreachable (); 1982} 1983 1984/* Update an entry in the vtable for BINFO, which is in the hierarchy 1985 dominated by T. FN has been overridden in BINFO; VIRTUALS points to the 1986 corresponding position in the BINFO_VIRTUALS list. */ 1987 1988static void 1989update_vtable_entry_for_fn (tree t, tree binfo, tree fn, tree* virtuals, 1990 unsigned ix) 1991{ 1992 tree b; 1993 tree overrider; 1994 tree delta; 1995 tree virtual_base; 1996 tree first_defn; 1997 tree overrider_fn, overrider_target; 1998 tree target_fn = DECL_THUNK_P (fn) ? THUNK_TARGET (fn) : fn; 1999 tree over_return, base_return; 2000 bool lost = false; 2001 2002 /* Find the nearest primary base (possibly binfo itself) which defines 2003 this function; this is the class the caller will convert to when 2004 calling FN through BINFO. */ 2005 for (b = binfo; ; b = get_primary_binfo (b)) 2006 { 2007 gcc_assert (b); 2008 if (look_for_overrides_here (BINFO_TYPE (b), target_fn)) 2009 break; 2010 2011 /* The nearest definition is from a lost primary. */ 2012 if (BINFO_LOST_PRIMARY_P (b)) 2013 lost = true; 2014 } 2015 first_defn = b; 2016 2017 /* Find the final overrider. */ 2018 overrider = find_final_overrider (TYPE_BINFO (t), b, target_fn); 2019 if (overrider == error_mark_node) 2020 { 2021 error ("no unique final overrider for %qD in %qT", target_fn, t); 2022 return; 2023 } 2024 overrider_target = overrider_fn = TREE_PURPOSE (overrider); 2025 2026 /* Check for adjusting covariant return types. */ 2027 over_return = TREE_TYPE (TREE_TYPE (overrider_target)); 2028 base_return = TREE_TYPE (TREE_TYPE (target_fn)); 2029 2030 if (POINTER_TYPE_P (over_return) 2031 && TREE_CODE (over_return) == TREE_CODE (base_return) 2032 && CLASS_TYPE_P (TREE_TYPE (over_return)) 2033 && CLASS_TYPE_P (TREE_TYPE (base_return)) 2034 /* If the overrider is invalid, don't even try. */ 2035 && !DECL_INVALID_OVERRIDER_P (overrider_target)) 2036 { 2037 /* If FN is a covariant thunk, we must figure out the adjustment 2038 to the final base FN was converting to. As OVERRIDER_TARGET might 2039 also be converting to the return type of FN, we have to 2040 combine the two conversions here. */ 2041 tree fixed_offset, virtual_offset; 2042 2043 over_return = TREE_TYPE (over_return); 2044 base_return = TREE_TYPE (base_return); 2045 2046 if (DECL_THUNK_P (fn)) 2047 { 2048 gcc_assert (DECL_RESULT_THUNK_P (fn)); 2049 fixed_offset = ssize_int (THUNK_FIXED_OFFSET (fn)); 2050 virtual_offset = THUNK_VIRTUAL_OFFSET (fn); 2051 } 2052 else 2053 fixed_offset = virtual_offset = NULL_TREE; 2054 2055 if (virtual_offset) 2056 /* Find the equivalent binfo within the return type of the 2057 overriding function. We will want the vbase offset from 2058 there. */ 2059 virtual_offset = binfo_for_vbase (BINFO_TYPE (virtual_offset), 2060 over_return); 2061 else if (!same_type_ignoring_top_level_qualifiers_p 2062 (over_return, base_return)) 2063 { 2064 /* There was no existing virtual thunk (which takes 2065 precedence). So find the binfo of the base function's 2066 return type within the overriding function's return type. 2067 We cannot call lookup base here, because we're inside a 2068 dfs_walk, and will therefore clobber the BINFO_MARKED 2069 flags. Fortunately we know the covariancy is valid (it 2070 has already been checked), so we can just iterate along 2071 the binfos, which have been chained in inheritance graph 2072 order. Of course it is lame that we have to repeat the 2073 search here anyway -- we should really be caching pieces 2074 of the vtable and avoiding this repeated work. */ 2075 tree thunk_binfo, base_binfo; 2076 2077 /* Find the base binfo within the overriding function's 2078 return type. We will always find a thunk_binfo, except 2079 when the covariancy is invalid (which we will have 2080 already diagnosed). */ 2081 for (base_binfo = TYPE_BINFO (base_return), 2082 thunk_binfo = TYPE_BINFO (over_return); 2083 thunk_binfo; 2084 thunk_binfo = TREE_CHAIN (thunk_binfo)) 2085 if (SAME_BINFO_TYPE_P (BINFO_TYPE (thunk_binfo), 2086 BINFO_TYPE (base_binfo))) 2087 break; 2088 2089 /* See if virtual inheritance is involved. */ 2090 for (virtual_offset = thunk_binfo; 2091 virtual_offset; 2092 virtual_offset = BINFO_INHERITANCE_CHAIN (virtual_offset)) 2093 if (BINFO_VIRTUAL_P (virtual_offset)) 2094 break; 2095 2096 if (virtual_offset 2097 || (thunk_binfo && !BINFO_OFFSET_ZEROP (thunk_binfo))) 2098 { 2099 tree offset = convert (ssizetype, BINFO_OFFSET (thunk_binfo)); 2100 2101 if (virtual_offset) 2102 { 2103 /* We convert via virtual base. Adjust the fixed 2104 offset to be from there. */ 2105 offset = size_diffop 2106 (offset, convert 2107 (ssizetype, BINFO_OFFSET (virtual_offset))); 2108 } 2109 if (fixed_offset) 2110 /* There was an existing fixed offset, this must be 2111 from the base just converted to, and the base the 2112 FN was thunking to. */ 2113 fixed_offset = size_binop (PLUS_EXPR, fixed_offset, offset); 2114 else 2115 fixed_offset = offset; 2116 } 2117 } 2118 2119 if (fixed_offset || virtual_offset) 2120 /* Replace the overriding function with a covariant thunk. We 2121 will emit the overriding function in its own slot as 2122 well. */ 2123 overrider_fn = make_thunk (overrider_target, /*this_adjusting=*/0, 2124 fixed_offset, virtual_offset); 2125 } 2126 else 2127 gcc_assert (!DECL_THUNK_P (fn)); 2128 2129 /* Assume that we will produce a thunk that convert all the way to 2130 the final overrider, and not to an intermediate virtual base. */ 2131 virtual_base = NULL_TREE; 2132 2133 /* See if we can convert to an intermediate virtual base first, and then 2134 use the vcall offset located there to finish the conversion. */ 2135 for (; b; b = BINFO_INHERITANCE_CHAIN (b)) 2136 { 2137 /* If we find the final overrider, then we can stop 2138 walking. */ 2139 if (SAME_BINFO_TYPE_P (BINFO_TYPE (b), 2140 BINFO_TYPE (TREE_VALUE (overrider)))) 2141 break; 2142 2143 /* If we find a virtual base, and we haven't yet found the 2144 overrider, then there is a virtual base between the 2145 declaring base (first_defn) and the final overrider. */ 2146 if (BINFO_VIRTUAL_P (b)) 2147 { 2148 virtual_base = b; 2149 break; 2150 } 2151 } 2152 2153 if (overrider_fn != overrider_target && !virtual_base) 2154 { 2155 /* The ABI specifies that a covariant thunk includes a mangling 2156 for a this pointer adjustment. This-adjusting thunks that 2157 override a function from a virtual base have a vcall 2158 adjustment. When the virtual base in question is a primary 2159 virtual base, we know the adjustments are zero, (and in the 2160 non-covariant case, we would not use the thunk). 2161 Unfortunately we didn't notice this could happen, when 2162 designing the ABI and so never mandated that such a covariant 2163 thunk should be emitted. Because we must use the ABI mandated 2164 name, we must continue searching from the binfo where we 2165 found the most recent definition of the function, towards the 2166 primary binfo which first introduced the function into the 2167 vtable. If that enters a virtual base, we must use a vcall 2168 this-adjusting thunk. Bleah! */ 2169 tree probe = first_defn; 2170 2171 while ((probe = get_primary_binfo (probe)) 2172 && (unsigned) list_length (BINFO_VIRTUALS (probe)) > ix) 2173 if (BINFO_VIRTUAL_P (probe)) 2174 virtual_base = probe; 2175 2176 if (virtual_base) 2177 /* Even if we find a virtual base, the correct delta is 2178 between the overrider and the binfo we're building a vtable 2179 for. */ 2180 goto virtual_covariant; 2181 } 2182 2183 /* Compute the constant adjustment to the `this' pointer. The 2184 `this' pointer, when this function is called, will point at BINFO 2185 (or one of its primary bases, which are at the same offset). */ 2186 if (virtual_base) 2187 /* The `this' pointer needs to be adjusted from the declaration to 2188 the nearest virtual base. */ 2189 delta = size_diffop (convert (ssizetype, BINFO_OFFSET (virtual_base)), 2190 convert (ssizetype, BINFO_OFFSET (first_defn))); 2191 else if (lost) 2192 /* If the nearest definition is in a lost primary, we don't need an 2193 entry in our vtable. Except possibly in a constructor vtable, 2194 if we happen to get our primary back. In that case, the offset 2195 will be zero, as it will be a primary base. */ 2196 delta = size_zero_node; 2197 else 2198 /* The `this' pointer needs to be adjusted from pointing to 2199 BINFO to pointing at the base where the final overrider 2200 appears. */ 2201 virtual_covariant: 2202 delta = size_diffop (convert (ssizetype, 2203 BINFO_OFFSET (TREE_VALUE (overrider))), 2204 convert (ssizetype, BINFO_OFFSET (binfo))); 2205 2206 modify_vtable_entry (t, binfo, overrider_fn, delta, virtuals); 2207 2208 if (virtual_base) 2209 BV_VCALL_INDEX (*virtuals) 2210 = get_vcall_index (overrider_target, BINFO_TYPE (virtual_base)); 2211 else 2212 BV_VCALL_INDEX (*virtuals) = NULL_TREE; 2213} 2214 2215/* Called from modify_all_vtables via dfs_walk. */ 2216 2217static tree 2218dfs_modify_vtables (tree binfo, void* data) 2219{ 2220 tree t = (tree) data; 2221 tree virtuals; 2222 tree old_virtuals; 2223 unsigned ix; 2224 2225 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))) 2226 /* A base without a vtable needs no modification, and its bases 2227 are uninteresting. */ 2228 return dfs_skip_bases; 2229 2230 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t) 2231 && !CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 2232 /* Don't do the primary vtable, if it's new. */ 2233 return NULL_TREE; 2234 2235 if (BINFO_PRIMARY_P (binfo) && !BINFO_VIRTUAL_P (binfo)) 2236 /* There's no need to modify the vtable for a non-virtual primary 2237 base; we're not going to use that vtable anyhow. We do still 2238 need to do this for virtual primary bases, as they could become 2239 non-primary in a construction vtable. */ 2240 return NULL_TREE; 2241 2242 make_new_vtable (t, binfo); 2243 2244 /* Now, go through each of the virtual functions in the virtual 2245 function table for BINFO. Find the final overrider, and update 2246 the BINFO_VIRTUALS list appropriately. */ 2247 for (ix = 0, virtuals = BINFO_VIRTUALS (binfo), 2248 old_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo))); 2249 virtuals; 2250 ix++, virtuals = TREE_CHAIN (virtuals), 2251 old_virtuals = TREE_CHAIN (old_virtuals)) 2252 update_vtable_entry_for_fn (t, 2253 binfo, 2254 BV_FN (old_virtuals), 2255 &virtuals, ix); 2256 2257 return NULL_TREE; 2258} 2259 2260/* Update all of the primary and secondary vtables for T. Create new 2261 vtables as required, and initialize their RTTI information. Each 2262 of the functions in VIRTUALS is declared in T and may override a 2263 virtual function from a base class; find and modify the appropriate 2264 entries to point to the overriding functions. Returns a list, in 2265 declaration order, of the virtual functions that are declared in T, 2266 but do not appear in the primary base class vtable, and which 2267 should therefore be appended to the end of the vtable for T. */ 2268 2269static tree 2270modify_all_vtables (tree t, tree virtuals) 2271{ 2272 tree binfo = TYPE_BINFO (t); 2273 tree *fnsp; 2274 2275 /* Update all of the vtables. */ 2276 dfs_walk_once (binfo, dfs_modify_vtables, NULL, t); 2277 2278 /* Add virtual functions not already in our primary vtable. These 2279 will be both those introduced by this class, and those overridden 2280 from secondary bases. It does not include virtuals merely 2281 inherited from secondary bases. */ 2282 for (fnsp = &virtuals; *fnsp; ) 2283 { 2284 tree fn = TREE_VALUE (*fnsp); 2285 2286 if (!value_member (fn, BINFO_VIRTUALS (binfo)) 2287 || DECL_VINDEX (fn) == error_mark_node) 2288 { 2289 /* We don't need to adjust the `this' pointer when 2290 calling this function. */ 2291 BV_DELTA (*fnsp) = integer_zero_node; 2292 BV_VCALL_INDEX (*fnsp) = NULL_TREE; 2293 2294 /* This is a function not already in our vtable. Keep it. */ 2295 fnsp = &TREE_CHAIN (*fnsp); 2296 } 2297 else 2298 /* We've already got an entry for this function. Skip it. */ 2299 *fnsp = TREE_CHAIN (*fnsp); 2300 } 2301 2302 return virtuals; 2303} 2304 2305/* Get the base virtual function declarations in T that have the 2306 indicated NAME. */ 2307 2308static tree 2309get_basefndecls (tree name, tree t) 2310{ 2311 tree methods; 2312 tree base_fndecls = NULL_TREE; 2313 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t)); 2314 int i; 2315 2316 /* Find virtual functions in T with the indicated NAME. */ 2317 i = lookup_fnfields_1 (t, name); 2318 if (i != -1) 2319 for (methods = VEC_index (tree, CLASSTYPE_METHOD_VEC (t), i); 2320 methods; 2321 methods = OVL_NEXT (methods)) 2322 { 2323 tree method = OVL_CURRENT (methods); 2324 2325 if (TREE_CODE (method) == FUNCTION_DECL 2326 && DECL_VINDEX (method)) 2327 base_fndecls = tree_cons (NULL_TREE, method, base_fndecls); 2328 } 2329 2330 if (base_fndecls) 2331 return base_fndecls; 2332 2333 for (i = 0; i < n_baseclasses; i++) 2334 { 2335 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (t), i)); 2336 base_fndecls = chainon (get_basefndecls (name, basetype), 2337 base_fndecls); 2338 } 2339 2340 return base_fndecls; 2341} 2342 2343/* If this declaration supersedes the declaration of 2344 a method declared virtual in the base class, then 2345 mark this field as being virtual as well. */ 2346 2347void 2348check_for_override (tree decl, tree ctype) 2349{ 2350 if (TREE_CODE (decl) == TEMPLATE_DECL) 2351 /* In [temp.mem] we have: 2352 2353 A specialization of a member function template does not 2354 override a virtual function from a base class. */ 2355 return; 2356 if ((DECL_DESTRUCTOR_P (decl) 2357 || IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) 2358 || DECL_CONV_FN_P (decl)) 2359 && look_for_overrides (ctype, decl) 2360 && !DECL_STATIC_FUNCTION_P (decl)) 2361 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor 2362 the error_mark_node so that we know it is an overriding 2363 function. */ 2364 DECL_VINDEX (decl) = decl; 2365 2366 if (DECL_VIRTUAL_P (decl)) 2367 { 2368 if (!DECL_VINDEX (decl)) 2369 DECL_VINDEX (decl) = error_mark_node; 2370 IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) = 1; 2371 } 2372} 2373 2374/* Warn about hidden virtual functions that are not overridden in t. 2375 We know that constructors and destructors don't apply. */ 2376 2377void 2378warn_hidden (tree t) 2379{ 2380 VEC(tree,gc) *method_vec = CLASSTYPE_METHOD_VEC (t); 2381 tree fns; 2382 size_t i; 2383 2384 /* We go through each separately named virtual function. */ 2385 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT; 2386 VEC_iterate (tree, method_vec, i, fns); 2387 ++i) 2388 { 2389 tree fn; 2390 tree name; 2391 tree fndecl; 2392 tree base_fndecls; 2393 tree base_binfo; 2394 tree binfo; 2395 int j; 2396 2397 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will 2398 have the same name. Figure out what name that is. */ 2399 name = DECL_NAME (OVL_CURRENT (fns)); 2400 /* There are no possibly hidden functions yet. */ 2401 base_fndecls = NULL_TREE; 2402 /* Iterate through all of the base classes looking for possibly 2403 hidden functions. */ 2404 for (binfo = TYPE_BINFO (t), j = 0; 2405 BINFO_BASE_ITERATE (binfo, j, base_binfo); j++) 2406 { 2407 tree basetype = BINFO_TYPE (base_binfo); 2408 base_fndecls = chainon (get_basefndecls (name, basetype), 2409 base_fndecls); 2410 } 2411 2412 /* If there are no functions to hide, continue. */ 2413 if (!base_fndecls) 2414 continue; 2415 2416 /* Remove any overridden functions. */ 2417 for (fn = fns; fn; fn = OVL_NEXT (fn)) 2418 { 2419 fndecl = OVL_CURRENT (fn); 2420 if (DECL_VINDEX (fndecl)) 2421 { 2422 tree *prev = &base_fndecls; 2423 2424 while (*prev) 2425 /* If the method from the base class has the same 2426 signature as the method from the derived class, it 2427 has been overridden. */ 2428 if (same_signature_p (fndecl, TREE_VALUE (*prev))) 2429 *prev = TREE_CHAIN (*prev); 2430 else 2431 prev = &TREE_CHAIN (*prev); 2432 } 2433 } 2434 2435 /* Now give a warning for all base functions without overriders, 2436 as they are hidden. */ 2437 while (base_fndecls) 2438 { 2439 /* Here we know it is a hider, and no overrider exists. */ 2440 warning (0, "%q+D was hidden", TREE_VALUE (base_fndecls)); 2441 warning (0, " by %q+D", fns); 2442 base_fndecls = TREE_CHAIN (base_fndecls); 2443 } 2444 } 2445} 2446 2447/* Check for things that are invalid. There are probably plenty of other 2448 things we should check for also. */ 2449 2450static void 2451finish_struct_anon (tree t) 2452{ 2453 tree field; 2454 2455 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field)) 2456 { 2457 if (TREE_STATIC (field)) 2458 continue; 2459 if (TREE_CODE (field) != FIELD_DECL) 2460 continue; 2461 2462 if (DECL_NAME (field) == NULL_TREE 2463 && ANON_AGGR_TYPE_P (TREE_TYPE (field))) 2464 { 2465 tree elt = TYPE_FIELDS (TREE_TYPE (field)); 2466 for (; elt; elt = TREE_CHAIN (elt)) 2467 { 2468 /* We're generally only interested in entities the user 2469 declared, but we also find nested classes by noticing 2470 the TYPE_DECL that we create implicitly. You're 2471 allowed to put one anonymous union inside another, 2472 though, so we explicitly tolerate that. We use 2473 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that 2474 we also allow unnamed types used for defining fields. */ 2475 if (DECL_ARTIFICIAL (elt) 2476 && (!DECL_IMPLICIT_TYPEDEF_P (elt) 2477 || TYPE_ANONYMOUS_P (TREE_TYPE (elt)))) 2478 continue; 2479 2480 if (TREE_CODE (elt) != FIELD_DECL) 2481 { 2482 pedwarn ("%q+#D invalid; an anonymous union can " 2483 "only have non-static data members", elt); 2484 continue; 2485 } 2486 2487 if (TREE_PRIVATE (elt)) 2488 pedwarn ("private member %q+#D in anonymous union", elt); 2489 else if (TREE_PROTECTED (elt)) 2490 pedwarn ("protected member %q+#D in anonymous union", elt); 2491 2492 TREE_PRIVATE (elt) = TREE_PRIVATE (field); 2493 TREE_PROTECTED (elt) = TREE_PROTECTED (field); 2494 } 2495 } 2496 } 2497} 2498 2499/* Add T to CLASSTYPE_DECL_LIST of current_class_type which 2500 will be used later during class template instantiation. 2501 When FRIEND_P is zero, T can be a static member data (VAR_DECL), 2502 a non-static member data (FIELD_DECL), a member function 2503 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE), 2504 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL) 2505 When FRIEND_P is nonzero, T is either a friend class 2506 (RECORD_TYPE, TEMPLATE_DECL) or a friend function 2507 (FUNCTION_DECL, TEMPLATE_DECL). */ 2508 2509void 2510maybe_add_class_template_decl_list (tree type, tree t, int friend_p) 2511{ 2512 /* Save some memory by not creating TREE_LIST if TYPE is not template. */ 2513 if (CLASSTYPE_TEMPLATE_INFO (type)) 2514 CLASSTYPE_DECL_LIST (type) 2515 = tree_cons (friend_p ? NULL_TREE : type, 2516 t, CLASSTYPE_DECL_LIST (type)); 2517} 2518 2519/* Create default constructors, assignment operators, and so forth for 2520 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR, 2521 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason, 2522 the class cannot have a default constructor, copy constructor 2523 taking a const reference argument, or an assignment operator taking 2524 a const reference, respectively. */ 2525 2526static void 2527add_implicitly_declared_members (tree t, 2528 int cant_have_const_cctor, 2529 int cant_have_const_assignment) 2530{ 2531 /* Destructor. */ 2532 if (!CLASSTYPE_DESTRUCTORS (t)) 2533 { 2534 /* In general, we create destructors lazily. */ 2535 CLASSTYPE_LAZY_DESTRUCTOR (t) = 1; 2536 /* However, if the implicit destructor is non-trivial 2537 destructor, we sometimes have to create it at this point. */ 2538 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)) 2539 { 2540 bool lazy_p = true; 2541 2542 if (TYPE_FOR_JAVA (t)) 2543 /* If this a Java class, any non-trivial destructor is 2544 invalid, even if compiler-generated. Therefore, if the 2545 destructor is non-trivial we create it now. */ 2546 lazy_p = false; 2547 else 2548 { 2549 tree binfo; 2550 tree base_binfo; 2551 int ix; 2552 2553 /* If the implicit destructor will be virtual, then we must 2554 generate it now because (unfortunately) we do not 2555 generate virtual tables lazily. */ 2556 binfo = TYPE_BINFO (t); 2557 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++) 2558 { 2559 tree base_type; 2560 tree dtor; 2561 2562 base_type = BINFO_TYPE (base_binfo); 2563 dtor = CLASSTYPE_DESTRUCTORS (base_type); 2564 if (dtor && DECL_VIRTUAL_P (dtor)) 2565 { 2566 lazy_p = false; 2567 break; 2568 } 2569 } 2570 } 2571 2572 /* If we can't get away with being lazy, generate the destructor 2573 now. */ 2574 if (!lazy_p) 2575 lazily_declare_fn (sfk_destructor, t); 2576 } 2577 } 2578 2579 /* Default constructor. */ 2580 if (! TYPE_HAS_CONSTRUCTOR (t)) 2581 { 2582 TYPE_HAS_DEFAULT_CONSTRUCTOR (t) = 1; 2583 CLASSTYPE_LAZY_DEFAULT_CTOR (t) = 1; 2584 } 2585 2586 /* Copy constructor. */ 2587 if (! TYPE_HAS_INIT_REF (t) && ! TYPE_FOR_JAVA (t)) 2588 { 2589 TYPE_HAS_INIT_REF (t) = 1; 2590 TYPE_HAS_CONST_INIT_REF (t) = !cant_have_const_cctor; 2591 CLASSTYPE_LAZY_COPY_CTOR (t) = 1; 2592 TYPE_HAS_CONSTRUCTOR (t) = 1; 2593 } 2594 2595 /* If there is no assignment operator, one will be created if and 2596 when it is needed. For now, just record whether or not the type 2597 of the parameter to the assignment operator will be a const or 2598 non-const reference. */ 2599 if (!TYPE_HAS_ASSIGN_REF (t) && !TYPE_FOR_JAVA (t)) 2600 { 2601 TYPE_HAS_ASSIGN_REF (t) = 1; 2602 TYPE_HAS_CONST_ASSIGN_REF (t) = !cant_have_const_assignment; 2603 CLASSTYPE_LAZY_ASSIGNMENT_OP (t) = 1; 2604 } 2605} 2606 2607/* Subroutine of finish_struct_1. Recursively count the number of fields 2608 in TYPE, including anonymous union members. */ 2609 2610static int 2611count_fields (tree fields) 2612{ 2613 tree x; 2614 int n_fields = 0; 2615 for (x = fields; x; x = TREE_CHAIN (x)) 2616 { 2617 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x))) 2618 n_fields += count_fields (TYPE_FIELDS (TREE_TYPE (x))); 2619 else 2620 n_fields += 1; 2621 } 2622 return n_fields; 2623} 2624 2625/* Subroutine of finish_struct_1. Recursively add all the fields in the 2626 TREE_LIST FIELDS to the SORTED_FIELDS_TYPE elts, starting at offset IDX. */ 2627 2628static int 2629add_fields_to_record_type (tree fields, struct sorted_fields_type *field_vec, int idx) 2630{ 2631 tree x; 2632 for (x = fields; x; x = TREE_CHAIN (x)) 2633 { 2634 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x))) 2635 idx = add_fields_to_record_type (TYPE_FIELDS (TREE_TYPE (x)), field_vec, idx); 2636 else 2637 field_vec->elts[idx++] = x; 2638 } 2639 return idx; 2640} 2641 2642/* FIELD is a bit-field. We are finishing the processing for its 2643 enclosing type. Issue any appropriate messages and set appropriate 2644 flags. */ 2645 2646static void 2647check_bitfield_decl (tree field) 2648{ 2649 tree type = TREE_TYPE (field); 2650 tree w = NULL_TREE; 2651 2652 /* Detect invalid bit-field type. */ 2653 if (DECL_INITIAL (field) 2654 && ! INTEGRAL_TYPE_P (TREE_TYPE (field))) 2655 { 2656 error ("bit-field %q+#D with non-integral type", field); 2657 w = error_mark_node; 2658 } 2659 2660 /* Detect and ignore out of range field width. */ 2661 if (DECL_INITIAL (field)) 2662 { 2663 w = DECL_INITIAL (field); 2664 2665 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */ 2666 STRIP_NOPS (w); 2667 2668 /* detect invalid field size. */ 2669 w = integral_constant_value (w); 2670 2671 if (TREE_CODE (w) != INTEGER_CST) 2672 { 2673 error ("bit-field %q+D width not an integer constant", field); 2674 w = error_mark_node; 2675 } 2676 else if (tree_int_cst_sgn (w) < 0) 2677 { 2678 error ("negative width in bit-field %q+D", field); 2679 w = error_mark_node; 2680 } 2681 else if (integer_zerop (w) && DECL_NAME (field) != 0) 2682 { 2683 error ("zero width for bit-field %q+D", field); 2684 w = error_mark_node; 2685 } 2686 else if (compare_tree_int (w, TYPE_PRECISION (type)) > 0 2687 && TREE_CODE (type) != ENUMERAL_TYPE 2688 && TREE_CODE (type) != BOOLEAN_TYPE) 2689 warning (0, "width of %q+D exceeds its type", field); 2690 else if (TREE_CODE (type) == ENUMERAL_TYPE 2691 && (0 > compare_tree_int (w, 2692 min_precision (TYPE_MIN_VALUE (type), 2693 TYPE_UNSIGNED (type))) 2694 || 0 > compare_tree_int (w, 2695 min_precision 2696 (TYPE_MAX_VALUE (type), 2697 TYPE_UNSIGNED (type))))) 2698 warning (0, "%q+D is too small to hold all values of %q#T", field, type); 2699 } 2700 2701 /* Remove the bit-field width indicator so that the rest of the 2702 compiler does not treat that value as an initializer. */ 2703 DECL_INITIAL (field) = NULL_TREE; 2704 2705 if (w != error_mark_node) 2706 { 2707 DECL_SIZE (field) = convert (bitsizetype, w); 2708 DECL_BIT_FIELD (field) = 1; 2709 } 2710 else 2711 { 2712 /* Non-bit-fields are aligned for their type. */ 2713 DECL_BIT_FIELD (field) = 0; 2714 CLEAR_DECL_C_BIT_FIELD (field); 2715 } 2716} 2717 2718/* FIELD is a non bit-field. We are finishing the processing for its 2719 enclosing type T. Issue any appropriate messages and set appropriate 2720 flags. */ 2721 2722static void 2723check_field_decl (tree field, 2724 tree t, 2725 int* cant_have_const_ctor, 2726 int* no_const_asn_ref, 2727 int* any_default_members) 2728{ 2729 tree type = strip_array_types (TREE_TYPE (field)); 2730 2731 /* An anonymous union cannot contain any fields which would change 2732 the settings of CANT_HAVE_CONST_CTOR and friends. */ 2733 if (ANON_UNION_TYPE_P (type)) 2734 ; 2735 /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous 2736 structs. So, we recurse through their fields here. */ 2737 else if (ANON_AGGR_TYPE_P (type)) 2738 { 2739 tree fields; 2740 2741 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields)) 2742 if (TREE_CODE (fields) == FIELD_DECL && !DECL_C_BIT_FIELD (field)) 2743 check_field_decl (fields, t, cant_have_const_ctor, 2744 no_const_asn_ref, any_default_members); 2745 } 2746 /* Check members with class type for constructors, destructors, 2747 etc. */ 2748 else if (CLASS_TYPE_P (type)) 2749 { 2750 /* Never let anything with uninheritable virtuals 2751 make it through without complaint. */ 2752 abstract_virtuals_error (field, type); 2753 2754 if (TREE_CODE (t) == UNION_TYPE) 2755 { 2756 if (TYPE_NEEDS_CONSTRUCTING (type)) 2757 error ("member %q+#D with constructor not allowed in union", 2758 field); 2759 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 2760 error ("member %q+#D with destructor not allowed in union", field); 2761 if (TYPE_HAS_COMPLEX_ASSIGN_REF (type)) 2762 error ("member %q+#D with copy assignment operator not allowed in union", 2763 field); 2764 } 2765 else 2766 { 2767 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (type); 2768 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) 2769 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type); 2770 TYPE_HAS_COMPLEX_ASSIGN_REF (t) |= TYPE_HAS_COMPLEX_ASSIGN_REF (type); 2771 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (type); 2772 } 2773 2774 if (!TYPE_HAS_CONST_INIT_REF (type)) 2775 *cant_have_const_ctor = 1; 2776 2777 if (!TYPE_HAS_CONST_ASSIGN_REF (type)) 2778 *no_const_asn_ref = 1; 2779 } 2780 if (DECL_INITIAL (field) != NULL_TREE) 2781 { 2782 /* `build_class_init_list' does not recognize 2783 non-FIELD_DECLs. */ 2784 if (TREE_CODE (t) == UNION_TYPE && any_default_members != 0) 2785 error ("multiple fields in union %qT initialized", t); 2786 *any_default_members = 1; 2787 } 2788} 2789 2790/* Check the data members (both static and non-static), class-scoped 2791 typedefs, etc., appearing in the declaration of T. Issue 2792 appropriate diagnostics. Sets ACCESS_DECLS to a list (in 2793 declaration order) of access declarations; each TREE_VALUE in this 2794 list is a USING_DECL. 2795 2796 In addition, set the following flags: 2797 2798 EMPTY_P 2799 The class is empty, i.e., contains no non-static data members. 2800 2801 CANT_HAVE_CONST_CTOR_P 2802 This class cannot have an implicitly generated copy constructor 2803 taking a const reference. 2804 2805 CANT_HAVE_CONST_ASN_REF 2806 This class cannot have an implicitly generated assignment 2807 operator taking a const reference. 2808 2809 All of these flags should be initialized before calling this 2810 function. 2811 2812 Returns a pointer to the end of the TYPE_FIELDs chain; additional 2813 fields can be added by adding to this chain. */ 2814 2815static void 2816check_field_decls (tree t, tree *access_decls, 2817 int *cant_have_const_ctor_p, 2818 int *no_const_asn_ref_p) 2819{ 2820 tree *field; 2821 tree *next; 2822 bool has_pointers; 2823 int any_default_members; 2824 int cant_pack = 0; 2825 2826 /* Assume there are no access declarations. */ 2827 *access_decls = NULL_TREE; 2828 /* Assume this class has no pointer members. */ 2829 has_pointers = false; 2830 /* Assume none of the members of this class have default 2831 initializations. */ 2832 any_default_members = 0; 2833 2834 for (field = &TYPE_FIELDS (t); *field; field = next) 2835 { 2836 tree x = *field; 2837 tree type = TREE_TYPE (x); 2838 2839 next = &TREE_CHAIN (x); 2840 2841 if (TREE_CODE (x) == USING_DECL) 2842 { 2843 /* Prune the access declaration from the list of fields. */ 2844 *field = TREE_CHAIN (x); 2845 2846 /* Save the access declarations for our caller. */ 2847 *access_decls = tree_cons (NULL_TREE, x, *access_decls); 2848 2849 /* Since we've reset *FIELD there's no reason to skip to the 2850 next field. */ 2851 next = field; 2852 continue; 2853 } 2854 2855 if (TREE_CODE (x) == TYPE_DECL 2856 || TREE_CODE (x) == TEMPLATE_DECL) 2857 continue; 2858 2859 /* If we've gotten this far, it's a data member, possibly static, 2860 or an enumerator. */ 2861 DECL_CONTEXT (x) = t; 2862 2863 /* When this goes into scope, it will be a non-local reference. */ 2864 DECL_NONLOCAL (x) = 1; 2865 2866 if (TREE_CODE (t) == UNION_TYPE) 2867 { 2868 /* [class.union] 2869 2870 If a union contains a static data member, or a member of 2871 reference type, the program is ill-formed. */ 2872 if (TREE_CODE (x) == VAR_DECL) 2873 { 2874 error ("%q+D may not be static because it is a member of a union", x); 2875 continue; 2876 } 2877 if (TREE_CODE (type) == REFERENCE_TYPE) 2878 { 2879 error ("%q+D may not have reference type %qT because" 2880 " it is a member of a union", 2881 x, type); 2882 continue; 2883 } 2884 } 2885 2886 /* ``A local class cannot have static data members.'' ARM 9.4 */ 2887 if (current_function_decl && TREE_STATIC (x)) 2888 error ("field %q+D in local class cannot be static", x); 2889 2890 /* Perform error checking that did not get done in 2891 grokdeclarator. */ 2892 if (TREE_CODE (type) == FUNCTION_TYPE) 2893 { 2894 error ("field %q+D invalidly declared function type", x); 2895 type = build_pointer_type (type); 2896 TREE_TYPE (x) = type; 2897 } 2898 else if (TREE_CODE (type) == METHOD_TYPE) 2899 { 2900 error ("field %q+D invalidly declared method type", x); 2901 type = build_pointer_type (type); 2902 TREE_TYPE (x) = type; 2903 } 2904 2905 if (type == error_mark_node) 2906 continue; 2907 2908 if (TREE_CODE (x) == CONST_DECL || TREE_CODE (x) == VAR_DECL) 2909 continue; 2910 2911 /* Now it can only be a FIELD_DECL. */ 2912 2913 if (TREE_PRIVATE (x) || TREE_PROTECTED (x)) 2914 CLASSTYPE_NON_AGGREGATE (t) = 1; 2915 2916 /* If this is of reference type, check if it needs an init. 2917 Also do a little ANSI jig if necessary. */ 2918 if (TREE_CODE (type) == REFERENCE_TYPE) 2919 { 2920 CLASSTYPE_NON_POD_P (t) = 1; 2921 if (DECL_INITIAL (x) == NULL_TREE) 2922 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1); 2923 2924 /* ARM $12.6.2: [A member initializer list] (or, for an 2925 aggregate, initialization by a brace-enclosed list) is the 2926 only way to initialize nonstatic const and reference 2927 members. */ 2928 TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1; 2929 2930 if (! TYPE_HAS_CONSTRUCTOR (t) && CLASSTYPE_NON_AGGREGATE (t) 2931 && extra_warnings) 2932 warning (0, "non-static reference %q+#D in class without a constructor", x); 2933 } 2934 2935 type = strip_array_types (type); 2936 2937 if (TYPE_PACKED (t)) 2938 { 2939 if (!pod_type_p (type) && !TYPE_PACKED (type)) 2940 { 2941 warning 2942 (0, 2943 "ignoring packed attribute because of unpacked non-POD field %q+#D", 2944 x); 2945 cant_pack = 1; 2946 } 2947 else if (TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT) 2948 DECL_PACKED (x) = 1; 2949 } 2950 2951 if (DECL_C_BIT_FIELD (x) && integer_zerop (DECL_INITIAL (x))) 2952 /* We don't treat zero-width bitfields as making a class 2953 non-empty. */ 2954 ; 2955 else 2956 { 2957 /* The class is non-empty. */ 2958 CLASSTYPE_EMPTY_P (t) = 0; 2959 /* The class is not even nearly empty. */ 2960 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 2961 /* If one of the data members contains an empty class, 2962 so does T. */ 2963 if (CLASS_TYPE_P (type) 2964 && CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type)) 2965 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1; 2966 } 2967 2968 /* This is used by -Weffc++ (see below). Warn only for pointers 2969 to members which might hold dynamic memory. So do not warn 2970 for pointers to functions or pointers to members. */ 2971 if (TYPE_PTR_P (type) 2972 && !TYPE_PTRFN_P (type) 2973 && !TYPE_PTR_TO_MEMBER_P (type)) 2974 has_pointers = true; 2975 2976 if (CLASS_TYPE_P (type)) 2977 { 2978 if (CLASSTYPE_REF_FIELDS_NEED_INIT (type)) 2979 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1); 2980 if (CLASSTYPE_READONLY_FIELDS_NEED_INIT (type)) 2981 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1); 2982 } 2983 2984 if (DECL_MUTABLE_P (x) || TYPE_HAS_MUTABLE_P (type)) 2985 CLASSTYPE_HAS_MUTABLE (t) = 1; 2986 2987 if (! pod_type_p (type)) 2988 /* DR 148 now allows pointers to members (which are POD themselves), 2989 to be allowed in POD structs. */ 2990 CLASSTYPE_NON_POD_P (t) = 1; 2991 2992 if (! zero_init_p (type)) 2993 CLASSTYPE_NON_ZERO_INIT_P (t) = 1; 2994 2995 /* If any field is const, the structure type is pseudo-const. */ 2996 if (CP_TYPE_CONST_P (type)) 2997 { 2998 C_TYPE_FIELDS_READONLY (t) = 1; 2999 if (DECL_INITIAL (x) == NULL_TREE) 3000 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1); 3001 3002 /* ARM $12.6.2: [A member initializer list] (or, for an 3003 aggregate, initialization by a brace-enclosed list) is the 3004 only way to initialize nonstatic const and reference 3005 members. */ 3006 TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1; 3007 3008 if (! TYPE_HAS_CONSTRUCTOR (t) && CLASSTYPE_NON_AGGREGATE (t) 3009 && extra_warnings) 3010 warning (0, "non-static const member %q+#D in class without a constructor", x); 3011 } 3012 /* A field that is pseudo-const makes the structure likewise. */ 3013 else if (CLASS_TYPE_P (type)) 3014 { 3015 C_TYPE_FIELDS_READONLY (t) |= C_TYPE_FIELDS_READONLY (type); 3016 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 3017 CLASSTYPE_READONLY_FIELDS_NEED_INIT (t) 3018 | CLASSTYPE_READONLY_FIELDS_NEED_INIT (type)); 3019 } 3020 3021 /* Core issue 80: A nonstatic data member is required to have a 3022 different name from the class iff the class has a 3023 user-defined constructor. */ 3024 if (constructor_name_p (DECL_NAME (x), t) && TYPE_HAS_CONSTRUCTOR (t)) 3025 pedwarn ("field %q+#D with same name as class", x); 3026 3027 /* We set DECL_C_BIT_FIELD in grokbitfield. 3028 If the type and width are valid, we'll also set DECL_BIT_FIELD. */ 3029 if (DECL_C_BIT_FIELD (x)) 3030 check_bitfield_decl (x); 3031 else 3032 check_field_decl (x, t, 3033 cant_have_const_ctor_p, 3034 no_const_asn_ref_p, 3035 &any_default_members); 3036 } 3037 3038 /* Effective C++ rule 11: if a class has dynamic memory held by pointers, 3039 it should also define a copy constructor and an assignment operator to 3040 implement the correct copy semantic (deep vs shallow, etc.). As it is 3041 not feasible to check whether the constructors do allocate dynamic memory 3042 and store it within members, we approximate the warning like this: 3043 3044 -- Warn only if there are members which are pointers 3045 -- Warn only if there is a non-trivial constructor (otherwise, 3046 there cannot be memory allocated). 3047 -- Warn only if there is a non-trivial destructor. We assume that the 3048 user at least implemented the cleanup correctly, and a destructor 3049 is needed to free dynamic memory. 3050 3051 This seems enough for practical purposes. */ 3052 if (warn_ecpp 3053 && has_pointers 3054 && TYPE_HAS_CONSTRUCTOR (t) 3055 && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) 3056 && !(TYPE_HAS_INIT_REF (t) && TYPE_HAS_ASSIGN_REF (t))) 3057 { 3058 warning (0, "%q#T has pointer data members", t); 3059 3060 if (! TYPE_HAS_INIT_REF (t)) 3061 { 3062 warning (0, " but does not override %<%T(const %T&)%>", t, t); 3063 if (! TYPE_HAS_ASSIGN_REF (t)) 3064 warning (0, " or %<operator=(const %T&)%>", t); 3065 } 3066 else if (! TYPE_HAS_ASSIGN_REF (t)) 3067 warning (0, " but does not override %<operator=(const %T&)%>", t); 3068 } 3069 3070 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */ 3071 if (cant_pack) 3072 TYPE_PACKED (t) = 0; 3073 3074 /* Check anonymous struct/anonymous union fields. */ 3075 finish_struct_anon (t); 3076 3077 /* We've built up the list of access declarations in reverse order. 3078 Fix that now. */ 3079 *access_decls = nreverse (*access_decls); 3080} 3081 3082/* If TYPE is an empty class type, records its OFFSET in the table of 3083 OFFSETS. */ 3084 3085static int 3086record_subobject_offset (tree type, tree offset, splay_tree offsets) 3087{ 3088 splay_tree_node n; 3089 3090 if (!is_empty_class (type)) 3091 return 0; 3092 3093 /* Record the location of this empty object in OFFSETS. */ 3094 n = splay_tree_lookup (offsets, (splay_tree_key) offset); 3095 if (!n) 3096 n = splay_tree_insert (offsets, 3097 (splay_tree_key) offset, 3098 (splay_tree_value) NULL_TREE); 3099 n->value = ((splay_tree_value) 3100 tree_cons (NULL_TREE, 3101 type, 3102 (tree) n->value)); 3103 3104 return 0; 3105} 3106 3107/* Returns nonzero if TYPE is an empty class type and there is 3108 already an entry in OFFSETS for the same TYPE as the same OFFSET. */ 3109 3110static int 3111check_subobject_offset (tree type, tree offset, splay_tree offsets) 3112{ 3113 splay_tree_node n; 3114 tree t; 3115 3116 if (!is_empty_class (type)) 3117 return 0; 3118 3119 /* Record the location of this empty object in OFFSETS. */ 3120 n = splay_tree_lookup (offsets, (splay_tree_key) offset); 3121 if (!n) 3122 return 0; 3123 3124 for (t = (tree) n->value; t; t = TREE_CHAIN (t)) 3125 if (same_type_p (TREE_VALUE (t), type)) 3126 return 1; 3127 3128 return 0; 3129} 3130 3131/* Walk through all the subobjects of TYPE (located at OFFSET). Call 3132 F for every subobject, passing it the type, offset, and table of 3133 OFFSETS. If VBASES_P is one, then virtual non-primary bases should 3134 be traversed. 3135 3136 If MAX_OFFSET is non-NULL, then subobjects with an offset greater 3137 than MAX_OFFSET will not be walked. 3138 3139 If F returns a nonzero value, the traversal ceases, and that value 3140 is returned. Otherwise, returns zero. */ 3141 3142static int 3143walk_subobject_offsets (tree type, 3144 subobject_offset_fn f, 3145 tree offset, 3146 splay_tree offsets, 3147 tree max_offset, 3148 int vbases_p) 3149{ 3150 int r = 0; 3151 tree type_binfo = NULL_TREE; 3152 3153 /* If this OFFSET is bigger than the MAX_OFFSET, then we should 3154 stop. */ 3155 if (max_offset && INT_CST_LT (max_offset, offset)) 3156 return 0; 3157 3158 if (type == error_mark_node) 3159 return 0; 3160 3161 if (!TYPE_P (type)) 3162 { 3163 if (abi_version_at_least (2)) 3164 type_binfo = type; 3165 type = BINFO_TYPE (type); 3166 } 3167 3168 if (CLASS_TYPE_P (type)) 3169 { 3170 tree field; 3171 tree binfo; 3172 int i; 3173 3174 /* Avoid recursing into objects that are not interesting. */ 3175 if (!CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type)) 3176 return 0; 3177 3178 /* Record the location of TYPE. */ 3179 r = (*f) (type, offset, offsets); 3180 if (r) 3181 return r; 3182 3183 /* Iterate through the direct base classes of TYPE. */ 3184 if (!type_binfo) 3185 type_binfo = TYPE_BINFO (type); 3186 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, binfo); i++) 3187 { 3188 tree binfo_offset; 3189 3190 if (abi_version_at_least (2) 3191 && BINFO_VIRTUAL_P (binfo)) 3192 continue; 3193 3194 if (!vbases_p 3195 && BINFO_VIRTUAL_P (binfo) 3196 && !BINFO_PRIMARY_P (binfo)) 3197 continue; 3198 3199 if (!abi_version_at_least (2)) 3200 binfo_offset = size_binop (PLUS_EXPR, 3201 offset, 3202 BINFO_OFFSET (binfo)); 3203 else 3204 { 3205 tree orig_binfo; 3206 /* We cannot rely on BINFO_OFFSET being set for the base 3207 class yet, but the offsets for direct non-virtual 3208 bases can be calculated by going back to the TYPE. */ 3209 orig_binfo = BINFO_BASE_BINFO (TYPE_BINFO (type), i); 3210 binfo_offset = size_binop (PLUS_EXPR, 3211 offset, 3212 BINFO_OFFSET (orig_binfo)); 3213 } 3214 3215 r = walk_subobject_offsets (binfo, 3216 f, 3217 binfo_offset, 3218 offsets, 3219 max_offset, 3220 (abi_version_at_least (2) 3221 ? /*vbases_p=*/0 : vbases_p)); 3222 if (r) 3223 return r; 3224 } 3225 3226 if (abi_version_at_least (2) && CLASSTYPE_VBASECLASSES (type)) 3227 { 3228 unsigned ix; 3229 VEC(tree,gc) *vbases; 3230 3231 /* Iterate through the virtual base classes of TYPE. In G++ 3232 3.2, we included virtual bases in the direct base class 3233 loop above, which results in incorrect results; the 3234 correct offsets for virtual bases are only known when 3235 working with the most derived type. */ 3236 if (vbases_p) 3237 for (vbases = CLASSTYPE_VBASECLASSES (type), ix = 0; 3238 VEC_iterate (tree, vbases, ix, binfo); ix++) 3239 { 3240 r = walk_subobject_offsets (binfo, 3241 f, 3242 size_binop (PLUS_EXPR, 3243 offset, 3244 BINFO_OFFSET (binfo)), 3245 offsets, 3246 max_offset, 3247 /*vbases_p=*/0); 3248 if (r) 3249 return r; 3250 } 3251 else 3252 { 3253 /* We still have to walk the primary base, if it is 3254 virtual. (If it is non-virtual, then it was walked 3255 above.) */ 3256 tree vbase = get_primary_binfo (type_binfo); 3257 3258 if (vbase && BINFO_VIRTUAL_P (vbase) 3259 && BINFO_PRIMARY_P (vbase) 3260 && BINFO_INHERITANCE_CHAIN (vbase) == type_binfo) 3261 { 3262 r = (walk_subobject_offsets 3263 (vbase, f, offset, 3264 offsets, max_offset, /*vbases_p=*/0)); 3265 if (r) 3266 return r; 3267 } 3268 } 3269 } 3270 3271 /* Iterate through the fields of TYPE. */ 3272 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) 3273 if (TREE_CODE (field) == FIELD_DECL && !DECL_ARTIFICIAL (field)) 3274 { 3275 tree field_offset; 3276 3277 if (abi_version_at_least (2)) 3278 field_offset = byte_position (field); 3279 else 3280 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */ 3281 field_offset = DECL_FIELD_OFFSET (field); 3282 3283 r = walk_subobject_offsets (TREE_TYPE (field), 3284 f, 3285 size_binop (PLUS_EXPR, 3286 offset, 3287 field_offset), 3288 offsets, 3289 max_offset, 3290 /*vbases_p=*/1); 3291 if (r) 3292 return r; 3293 } 3294 } 3295 else if (TREE_CODE (type) == ARRAY_TYPE) 3296 { 3297 tree element_type = strip_array_types (type); 3298 tree domain = TYPE_DOMAIN (type); 3299 tree index; 3300 3301 /* Avoid recursing into objects that are not interesting. */ 3302 if (!CLASS_TYPE_P (element_type) 3303 || !CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type)) 3304 return 0; 3305 3306 /* Step through each of the elements in the array. */ 3307 for (index = size_zero_node; 3308 /* G++ 3.2 had an off-by-one error here. */ 3309 (abi_version_at_least (2) 3310 ? !INT_CST_LT (TYPE_MAX_VALUE (domain), index) 3311 : INT_CST_LT (index, TYPE_MAX_VALUE (domain))); 3312 index = size_binop (PLUS_EXPR, index, size_one_node)) 3313 { 3314 r = walk_subobject_offsets (TREE_TYPE (type), 3315 f, 3316 offset, 3317 offsets, 3318 max_offset, 3319 /*vbases_p=*/1); 3320 if (r) 3321 return r; 3322 offset = size_binop (PLUS_EXPR, offset, 3323 TYPE_SIZE_UNIT (TREE_TYPE (type))); 3324 /* If this new OFFSET is bigger than the MAX_OFFSET, then 3325 there's no point in iterating through the remaining 3326 elements of the array. */ 3327 if (max_offset && INT_CST_LT (max_offset, offset)) 3328 break; 3329 } 3330 } 3331 3332 return 0; 3333} 3334 3335/* Record all of the empty subobjects of TYPE (either a type or a 3336 binfo). If IS_DATA_MEMBER is true, then a non-static data member 3337 is being placed at OFFSET; otherwise, it is a base class that is 3338 being placed at OFFSET. */ 3339 3340static void 3341record_subobject_offsets (tree type, 3342 tree offset, 3343 splay_tree offsets, 3344 bool is_data_member) 3345{ 3346 tree max_offset; 3347 /* If recording subobjects for a non-static data member or a 3348 non-empty base class , we do not need to record offsets beyond 3349 the size of the biggest empty class. Additional data members 3350 will go at the end of the class. Additional base classes will go 3351 either at offset zero (if empty, in which case they cannot 3352 overlap with offsets past the size of the biggest empty class) or 3353 at the end of the class. 3354 3355 However, if we are placing an empty base class, then we must record 3356 all offsets, as either the empty class is at offset zero (where 3357 other empty classes might later be placed) or at the end of the 3358 class (where other objects might then be placed, so other empty 3359 subobjects might later overlap). */ 3360 if (is_data_member 3361 || !is_empty_class (BINFO_TYPE (type))) 3362 max_offset = sizeof_biggest_empty_class; 3363 else 3364 max_offset = NULL_TREE; 3365 walk_subobject_offsets (type, record_subobject_offset, offset, 3366 offsets, max_offset, is_data_member); 3367} 3368 3369/* Returns nonzero if any of the empty subobjects of TYPE (located at 3370 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero, 3371 virtual bases of TYPE are examined. */ 3372 3373static int 3374layout_conflict_p (tree type, 3375 tree offset, 3376 splay_tree offsets, 3377 int vbases_p) 3378{ 3379 splay_tree_node max_node; 3380 3381 /* Get the node in OFFSETS that indicates the maximum offset where 3382 an empty subobject is located. */ 3383 max_node = splay_tree_max (offsets); 3384 /* If there aren't any empty subobjects, then there's no point in 3385 performing this check. */ 3386 if (!max_node) 3387 return 0; 3388 3389 return walk_subobject_offsets (type, check_subobject_offset, offset, 3390 offsets, (tree) (max_node->key), 3391 vbases_p); 3392} 3393 3394/* DECL is a FIELD_DECL corresponding either to a base subobject of a 3395 non-static data member of the type indicated by RLI. BINFO is the 3396 binfo corresponding to the base subobject, OFFSETS maps offsets to 3397 types already located at those offsets. This function determines 3398 the position of the DECL. */ 3399 3400static void 3401layout_nonempty_base_or_field (record_layout_info rli, 3402 tree decl, 3403 tree binfo, 3404 splay_tree offsets) 3405{ 3406 tree offset = NULL_TREE; 3407 bool field_p; 3408 tree type; 3409 3410 if (binfo) 3411 { 3412 /* For the purposes of determining layout conflicts, we want to 3413 use the class type of BINFO; TREE_TYPE (DECL) will be the 3414 CLASSTYPE_AS_BASE version, which does not contain entries for 3415 zero-sized bases. */ 3416 type = TREE_TYPE (binfo); 3417 field_p = false; 3418 } 3419 else 3420 { 3421 type = TREE_TYPE (decl); 3422 field_p = true; 3423 } 3424 3425 /* Try to place the field. It may take more than one try if we have 3426 a hard time placing the field without putting two objects of the 3427 same type at the same address. */ 3428 while (1) 3429 { 3430 struct record_layout_info_s old_rli = *rli; 3431 3432 /* Place this field. */ 3433 place_field (rli, decl); 3434 offset = byte_position (decl); 3435 3436 /* We have to check to see whether or not there is already 3437 something of the same type at the offset we're about to use. 3438 For example, consider: 3439 3440 struct S {}; 3441 struct T : public S { int i; }; 3442 struct U : public S, public T {}; 3443 3444 Here, we put S at offset zero in U. Then, we can't put T at 3445 offset zero -- its S component would be at the same address 3446 as the S we already allocated. So, we have to skip ahead. 3447 Since all data members, including those whose type is an 3448 empty class, have nonzero size, any overlap can happen only 3449 with a direct or indirect base-class -- it can't happen with 3450 a data member. */ 3451 /* In a union, overlap is permitted; all members are placed at 3452 offset zero. */ 3453 if (TREE_CODE (rli->t) == UNION_TYPE) 3454 break; 3455 /* G++ 3.2 did not check for overlaps when placing a non-empty 3456 virtual base. */ 3457 if (!abi_version_at_least (2) && binfo && BINFO_VIRTUAL_P (binfo)) 3458 break; 3459 if (layout_conflict_p (field_p ? type : binfo, offset, 3460 offsets, field_p)) 3461 { 3462 /* Strip off the size allocated to this field. That puts us 3463 at the first place we could have put the field with 3464 proper alignment. */ 3465 *rli = old_rli; 3466 3467 /* Bump up by the alignment required for the type. */ 3468 rli->bitpos 3469 = size_binop (PLUS_EXPR, rli->bitpos, 3470 bitsize_int (binfo 3471 ? CLASSTYPE_ALIGN (type) 3472 : TYPE_ALIGN (type))); 3473 normalize_rli (rli); 3474 } 3475 else 3476 /* There was no conflict. We're done laying out this field. */ 3477 break; 3478 } 3479 3480 /* Now that we know where it will be placed, update its 3481 BINFO_OFFSET. */ 3482 if (binfo && CLASS_TYPE_P (BINFO_TYPE (binfo))) 3483 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at 3484 this point because their BINFO_OFFSET is copied from another 3485 hierarchy. Therefore, we may not need to add the entire 3486 OFFSET. */ 3487 propagate_binfo_offsets (binfo, 3488 size_diffop (convert (ssizetype, offset), 3489 convert (ssizetype, 3490 BINFO_OFFSET (binfo)))); 3491} 3492 3493/* Returns true if TYPE is empty and OFFSET is nonzero. */ 3494 3495static int 3496empty_base_at_nonzero_offset_p (tree type, 3497 tree offset, 3498 splay_tree offsets ATTRIBUTE_UNUSED) 3499{ 3500 return is_empty_class (type) && !integer_zerop (offset); 3501} 3502 3503/* Layout the empty base BINFO. EOC indicates the byte currently just 3504 past the end of the class, and should be correctly aligned for a 3505 class of the type indicated by BINFO; OFFSETS gives the offsets of 3506 the empty bases allocated so far. T is the most derived 3507 type. Return nonzero iff we added it at the end. */ 3508 3509static bool 3510layout_empty_base (tree binfo, tree eoc, splay_tree offsets) 3511{ 3512 tree alignment; 3513 tree basetype = BINFO_TYPE (binfo); 3514 bool atend = false; 3515 3516 /* This routine should only be used for empty classes. */ 3517 gcc_assert (is_empty_class (basetype)); 3518 alignment = ssize_int (CLASSTYPE_ALIGN_UNIT (basetype)); 3519 3520 if (!integer_zerop (BINFO_OFFSET (binfo))) 3521 { 3522 if (abi_version_at_least (2)) 3523 propagate_binfo_offsets 3524 (binfo, size_diffop (size_zero_node, BINFO_OFFSET (binfo))); 3525 else if (warn_abi) 3526 warning (0, "offset of empty base %qT may not be ABI-compliant and may" 3527 "change in a future version of GCC", 3528 BINFO_TYPE (binfo)); 3529 } 3530 3531 /* This is an empty base class. We first try to put it at offset 3532 zero. */ 3533 if (layout_conflict_p (binfo, 3534 BINFO_OFFSET (binfo), 3535 offsets, 3536 /*vbases_p=*/0)) 3537 { 3538 /* That didn't work. Now, we move forward from the next 3539 available spot in the class. */ 3540 atend = true; 3541 propagate_binfo_offsets (binfo, convert (ssizetype, eoc)); 3542 while (1) 3543 { 3544 if (!layout_conflict_p (binfo, 3545 BINFO_OFFSET (binfo), 3546 offsets, 3547 /*vbases_p=*/0)) 3548 /* We finally found a spot where there's no overlap. */ 3549 break; 3550 3551 /* There's overlap here, too. Bump along to the next spot. */ 3552 propagate_binfo_offsets (binfo, alignment); 3553 } 3554 } 3555 return atend; 3556} 3557 3558/* Layout the base given by BINFO in the class indicated by RLI. 3559 *BASE_ALIGN is a running maximum of the alignments of 3560 any base class. OFFSETS gives the location of empty base 3561 subobjects. T is the most derived type. Return nonzero if the new 3562 object cannot be nearly-empty. A new FIELD_DECL is inserted at 3563 *NEXT_FIELD, unless BINFO is for an empty base class. 3564 3565 Returns the location at which the next field should be inserted. */ 3566 3567static tree * 3568build_base_field (record_layout_info rli, tree binfo, 3569 splay_tree offsets, tree *next_field) 3570{ 3571 tree t = rli->t; 3572 tree basetype = BINFO_TYPE (binfo); 3573 3574 if (!COMPLETE_TYPE_P (basetype)) 3575 /* This error is now reported in xref_tag, thus giving better 3576 location information. */ 3577 return next_field; 3578 3579 /* Place the base class. */ 3580 if (!is_empty_class (basetype)) 3581 { 3582 tree decl; 3583 3584 /* The containing class is non-empty because it has a non-empty 3585 base class. */ 3586 CLASSTYPE_EMPTY_P (t) = 0; 3587 3588 /* Create the FIELD_DECL. */ 3589 decl = build_decl (FIELD_DECL, NULL_TREE, CLASSTYPE_AS_BASE (basetype)); 3590 DECL_ARTIFICIAL (decl) = 1; 3591 DECL_IGNORED_P (decl) = 1; 3592 DECL_FIELD_CONTEXT (decl) = t; 3593 DECL_SIZE (decl) = CLASSTYPE_SIZE (basetype); 3594 DECL_SIZE_UNIT (decl) = CLASSTYPE_SIZE_UNIT (basetype); 3595 DECL_ALIGN (decl) = CLASSTYPE_ALIGN (basetype); 3596 DECL_USER_ALIGN (decl) = CLASSTYPE_USER_ALIGN (basetype); 3597 DECL_MODE (decl) = TYPE_MODE (basetype); 3598 DECL_FIELD_IS_BASE (decl) = 1; 3599 3600 /* Try to place the field. It may take more than one try if we 3601 have a hard time placing the field without putting two 3602 objects of the same type at the same address. */ 3603 layout_nonempty_base_or_field (rli, decl, binfo, offsets); 3604 /* Add the new FIELD_DECL to the list of fields for T. */ 3605 TREE_CHAIN (decl) = *next_field; 3606 *next_field = decl; 3607 next_field = &TREE_CHAIN (decl); 3608 } 3609 else 3610 { 3611 tree eoc; 3612 bool atend; 3613 3614 /* On some platforms (ARM), even empty classes will not be 3615 byte-aligned. */ 3616 eoc = round_up (rli_size_unit_so_far (rli), 3617 CLASSTYPE_ALIGN_UNIT (basetype)); 3618 atend = layout_empty_base (binfo, eoc, offsets); 3619 /* A nearly-empty class "has no proper base class that is empty, 3620 not morally virtual, and at an offset other than zero." */ 3621 if (!BINFO_VIRTUAL_P (binfo) && CLASSTYPE_NEARLY_EMPTY_P (t)) 3622 { 3623 if (atend) 3624 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 3625 /* The check above (used in G++ 3.2) is insufficient because 3626 an empty class placed at offset zero might itself have an 3627 empty base at a nonzero offset. */ 3628 else if (walk_subobject_offsets (basetype, 3629 empty_base_at_nonzero_offset_p, 3630 size_zero_node, 3631 /*offsets=*/NULL, 3632 /*max_offset=*/NULL_TREE, 3633 /*vbases_p=*/true)) 3634 { 3635 if (abi_version_at_least (2)) 3636 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 3637 else if (warn_abi) 3638 warning (0, "class %qT will be considered nearly empty in a " 3639 "future version of GCC", t); 3640 } 3641 } 3642 3643 /* We do not create a FIELD_DECL for empty base classes because 3644 it might overlap some other field. We want to be able to 3645 create CONSTRUCTORs for the class by iterating over the 3646 FIELD_DECLs, and the back end does not handle overlapping 3647 FIELD_DECLs. */ 3648 3649 /* An empty virtual base causes a class to be non-empty 3650 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P 3651 here because that was already done when the virtual table 3652 pointer was created. */ 3653 } 3654 3655 /* Record the offsets of BINFO and its base subobjects. */ 3656 record_subobject_offsets (binfo, 3657 BINFO_OFFSET (binfo), 3658 offsets, 3659 /*is_data_member=*/false); 3660 3661 return next_field; 3662} 3663 3664/* Layout all of the non-virtual base classes. Record empty 3665 subobjects in OFFSETS. T is the most derived type. Return nonzero 3666 if the type cannot be nearly empty. The fields created 3667 corresponding to the base classes will be inserted at 3668 *NEXT_FIELD. */ 3669 3670static void 3671build_base_fields (record_layout_info rli, 3672 splay_tree offsets, tree *next_field) 3673{ 3674 /* Chain to hold all the new FIELD_DECLs which stand in for base class 3675 subobjects. */ 3676 tree t = rli->t; 3677 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t)); 3678 int i; 3679 3680 /* The primary base class is always allocated first. */ 3681 if (CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 3682 next_field = build_base_field (rli, CLASSTYPE_PRIMARY_BINFO (t), 3683 offsets, next_field); 3684 3685 /* Now allocate the rest of the bases. */ 3686 for (i = 0; i < n_baseclasses; ++i) 3687 { 3688 tree base_binfo; 3689 3690 base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i); 3691 3692 /* The primary base was already allocated above, so we don't 3693 need to allocate it again here. */ 3694 if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t)) 3695 continue; 3696 3697 /* Virtual bases are added at the end (a primary virtual base 3698 will have already been added). */ 3699 if (BINFO_VIRTUAL_P (base_binfo)) 3700 continue; 3701 3702 next_field = build_base_field (rli, base_binfo, 3703 offsets, next_field); 3704 } 3705} 3706 3707/* Go through the TYPE_METHODS of T issuing any appropriate 3708 diagnostics, figuring out which methods override which other 3709 methods, and so forth. */ 3710 3711static void 3712check_methods (tree t) 3713{ 3714 tree x; 3715 3716 for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x)) 3717 { 3718 check_for_override (x, t); 3719 if (DECL_PURE_VIRTUAL_P (x) && ! DECL_VINDEX (x)) 3720 error ("initializer specified for non-virtual method %q+D", x); 3721 /* The name of the field is the original field name 3722 Save this in auxiliary field for later overloading. */ 3723 if (DECL_VINDEX (x)) 3724 { 3725 TYPE_POLYMORPHIC_P (t) = 1; 3726 if (DECL_PURE_VIRTUAL_P (x)) 3727 VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x); 3728 } 3729 /* All user-declared destructors are non-trivial. */ 3730 if (DECL_DESTRUCTOR_P (x)) 3731 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = 1; 3732 } 3733} 3734 3735/* FN is a constructor or destructor. Clone the declaration to create 3736 a specialized in-charge or not-in-charge version, as indicated by 3737 NAME. */ 3738 3739static tree 3740build_clone (tree fn, tree name) 3741{ 3742 tree parms; 3743 tree clone; 3744 3745 /* Copy the function. */ 3746 clone = copy_decl (fn); 3747 /* Remember where this function came from. */ 3748 DECL_CLONED_FUNCTION (clone) = fn; 3749 DECL_ABSTRACT_ORIGIN (clone) = fn; 3750 /* Reset the function name. */ 3751 DECL_NAME (clone) = name; 3752 SET_DECL_ASSEMBLER_NAME (clone, NULL_TREE); 3753 /* There's no pending inline data for this function. */ 3754 DECL_PENDING_INLINE_INFO (clone) = NULL; 3755 DECL_PENDING_INLINE_P (clone) = 0; 3756 /* And it hasn't yet been deferred. */ 3757 DECL_DEFERRED_FN (clone) = 0; 3758 3759 /* The base-class destructor is not virtual. */ 3760 if (name == base_dtor_identifier) 3761 { 3762 DECL_VIRTUAL_P (clone) = 0; 3763 if (TREE_CODE (clone) != TEMPLATE_DECL) 3764 DECL_VINDEX (clone) = NULL_TREE; 3765 } 3766 3767 /* If there was an in-charge parameter, drop it from the function 3768 type. */ 3769 if (DECL_HAS_IN_CHARGE_PARM_P (clone)) 3770 { 3771 tree basetype; 3772 tree parmtypes; 3773 tree exceptions; 3774 3775 exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone)); 3776 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone)); 3777 parmtypes = TYPE_ARG_TYPES (TREE_TYPE (clone)); 3778 /* Skip the `this' parameter. */ 3779 parmtypes = TREE_CHAIN (parmtypes); 3780 /* Skip the in-charge parameter. */ 3781 parmtypes = TREE_CHAIN (parmtypes); 3782 /* And the VTT parm, in a complete [cd]tor. */ 3783 if (DECL_HAS_VTT_PARM_P (fn) 3784 && ! DECL_NEEDS_VTT_PARM_P (clone)) 3785 parmtypes = TREE_CHAIN (parmtypes); 3786 /* If this is subobject constructor or destructor, add the vtt 3787 parameter. */ 3788 TREE_TYPE (clone) 3789 = build_method_type_directly (basetype, 3790 TREE_TYPE (TREE_TYPE (clone)), 3791 parmtypes); 3792 if (exceptions) 3793 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), 3794 exceptions); 3795 TREE_TYPE (clone) 3796 = cp_build_type_attribute_variant (TREE_TYPE (clone), 3797 TYPE_ATTRIBUTES (TREE_TYPE (fn))); 3798 } 3799 3800 /* Copy the function parameters. But, DECL_ARGUMENTS on a TEMPLATE_DECL 3801 aren't function parameters; those are the template parameters. */ 3802 if (TREE_CODE (clone) != TEMPLATE_DECL) 3803 { 3804 DECL_ARGUMENTS (clone) = copy_list (DECL_ARGUMENTS (clone)); 3805 /* Remove the in-charge parameter. */ 3806 if (DECL_HAS_IN_CHARGE_PARM_P (clone)) 3807 { 3808 TREE_CHAIN (DECL_ARGUMENTS (clone)) 3809 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone))); 3810 DECL_HAS_IN_CHARGE_PARM_P (clone) = 0; 3811 } 3812 /* And the VTT parm, in a complete [cd]tor. */ 3813 if (DECL_HAS_VTT_PARM_P (fn)) 3814 { 3815 if (DECL_NEEDS_VTT_PARM_P (clone)) 3816 DECL_HAS_VTT_PARM_P (clone) = 1; 3817 else 3818 { 3819 TREE_CHAIN (DECL_ARGUMENTS (clone)) 3820 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone))); 3821 DECL_HAS_VTT_PARM_P (clone) = 0; 3822 } 3823 } 3824 3825 for (parms = DECL_ARGUMENTS (clone); parms; parms = TREE_CHAIN (parms)) 3826 { 3827 DECL_CONTEXT (parms) = clone; 3828 cxx_dup_lang_specific_decl (parms); 3829 } 3830 } 3831 3832 /* Create the RTL for this function. */ 3833 SET_DECL_RTL (clone, NULL_RTX); 3834 rest_of_decl_compilation (clone, /*top_level=*/1, at_eof); 3835 3836 /* Make it easy to find the CLONE given the FN. */ 3837 TREE_CHAIN (clone) = TREE_CHAIN (fn); 3838 TREE_CHAIN (fn) = clone; 3839 3840 /* If this is a template, handle the DECL_TEMPLATE_RESULT as well. */ 3841 if (TREE_CODE (clone) == TEMPLATE_DECL) 3842 { 3843 tree result; 3844 3845 DECL_TEMPLATE_RESULT (clone) 3846 = build_clone (DECL_TEMPLATE_RESULT (clone), name); 3847 result = DECL_TEMPLATE_RESULT (clone); 3848 DECL_TEMPLATE_INFO (result) = copy_node (DECL_TEMPLATE_INFO (result)); 3849 DECL_TI_TEMPLATE (result) = clone; 3850 } 3851 else if (pch_file) 3852 note_decl_for_pch (clone); 3853 3854 return clone; 3855} 3856 3857/* Produce declarations for all appropriate clones of FN. If 3858 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the 3859 CLASTYPE_METHOD_VEC as well. */ 3860 3861void 3862clone_function_decl (tree fn, int update_method_vec_p) 3863{ 3864 tree clone; 3865 3866 /* Avoid inappropriate cloning. */ 3867 if (TREE_CHAIN (fn) 3868 && DECL_CLONED_FUNCTION (TREE_CHAIN (fn))) 3869 return; 3870 3871 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn)) 3872 { 3873 /* For each constructor, we need two variants: an in-charge version 3874 and a not-in-charge version. */ 3875 clone = build_clone (fn, complete_ctor_identifier); 3876 if (update_method_vec_p) 3877 add_method (DECL_CONTEXT (clone), clone, NULL_TREE); 3878 clone = build_clone (fn, base_ctor_identifier); 3879 if (update_method_vec_p) 3880 add_method (DECL_CONTEXT (clone), clone, NULL_TREE); 3881 } 3882 else 3883 { 3884 gcc_assert (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)); 3885 3886 /* For each destructor, we need three variants: an in-charge 3887 version, a not-in-charge version, and an in-charge deleting 3888 version. We clone the deleting version first because that 3889 means it will go second on the TYPE_METHODS list -- and that 3890 corresponds to the correct layout order in the virtual 3891 function table. 3892 3893 For a non-virtual destructor, we do not build a deleting 3894 destructor. */ 3895 if (DECL_VIRTUAL_P (fn)) 3896 { 3897 clone = build_clone (fn, deleting_dtor_identifier); 3898 if (update_method_vec_p) 3899 add_method (DECL_CONTEXT (clone), clone, NULL_TREE); 3900 } 3901 clone = build_clone (fn, complete_dtor_identifier); 3902 if (update_method_vec_p) 3903 add_method (DECL_CONTEXT (clone), clone, NULL_TREE); 3904 clone = build_clone (fn, base_dtor_identifier); 3905 if (update_method_vec_p) 3906 add_method (DECL_CONTEXT (clone), clone, NULL_TREE); 3907 } 3908 3909 /* Note that this is an abstract function that is never emitted. */ 3910 DECL_ABSTRACT (fn) = 1; 3911} 3912 3913/* DECL is an in charge constructor, which is being defined. This will 3914 have had an in class declaration, from whence clones were 3915 declared. An out-of-class definition can specify additional default 3916 arguments. As it is the clones that are involved in overload 3917 resolution, we must propagate the information from the DECL to its 3918 clones. */ 3919 3920void 3921adjust_clone_args (tree decl) 3922{ 3923 tree clone; 3924 3925 for (clone = TREE_CHAIN (decl); clone && DECL_CLONED_FUNCTION (clone); 3926 clone = TREE_CHAIN (clone)) 3927 { 3928 tree orig_clone_parms = TYPE_ARG_TYPES (TREE_TYPE (clone)); 3929 tree orig_decl_parms = TYPE_ARG_TYPES (TREE_TYPE (decl)); 3930 tree decl_parms, clone_parms; 3931 3932 clone_parms = orig_clone_parms; 3933 3934 /* Skip the 'this' parameter. */ 3935 orig_clone_parms = TREE_CHAIN (orig_clone_parms); 3936 orig_decl_parms = TREE_CHAIN (orig_decl_parms); 3937 3938 if (DECL_HAS_IN_CHARGE_PARM_P (decl)) 3939 orig_decl_parms = TREE_CHAIN (orig_decl_parms); 3940 if (DECL_HAS_VTT_PARM_P (decl)) 3941 orig_decl_parms = TREE_CHAIN (orig_decl_parms); 3942 3943 clone_parms = orig_clone_parms; 3944 if (DECL_HAS_VTT_PARM_P (clone)) 3945 clone_parms = TREE_CHAIN (clone_parms); 3946 3947 for (decl_parms = orig_decl_parms; decl_parms; 3948 decl_parms = TREE_CHAIN (decl_parms), 3949 clone_parms = TREE_CHAIN (clone_parms)) 3950 { 3951 gcc_assert (same_type_p (TREE_TYPE (decl_parms), 3952 TREE_TYPE (clone_parms))); 3953 3954 if (TREE_PURPOSE (decl_parms) && !TREE_PURPOSE (clone_parms)) 3955 { 3956 /* A default parameter has been added. Adjust the 3957 clone's parameters. */ 3958 tree exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone)); 3959 tree basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone)); 3960 tree type; 3961 3962 clone_parms = orig_decl_parms; 3963 3964 if (DECL_HAS_VTT_PARM_P (clone)) 3965 { 3966 clone_parms = tree_cons (TREE_PURPOSE (orig_clone_parms), 3967 TREE_VALUE (orig_clone_parms), 3968 clone_parms); 3969 TREE_TYPE (clone_parms) = TREE_TYPE (orig_clone_parms); 3970 } 3971 type = build_method_type_directly (basetype, 3972 TREE_TYPE (TREE_TYPE (clone)), 3973 clone_parms); 3974 if (exceptions) 3975 type = build_exception_variant (type, exceptions); 3976 TREE_TYPE (clone) = type; 3977 3978 clone_parms = NULL_TREE; 3979 break; 3980 } 3981 } 3982 gcc_assert (!clone_parms); 3983 } 3984} 3985 3986/* For each of the constructors and destructors in T, create an 3987 in-charge and not-in-charge variant. */ 3988 3989static void 3990clone_constructors_and_destructors (tree t) 3991{ 3992 tree fns; 3993 3994 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail 3995 out now. */ 3996 if (!CLASSTYPE_METHOD_VEC (t)) 3997 return; 3998 3999 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns)) 4000 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1); 4001 for (fns = CLASSTYPE_DESTRUCTORS (t); fns; fns = OVL_NEXT (fns)) 4002 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1); 4003} 4004 4005/* Remove all zero-width bit-fields from T. */ 4006 4007static void 4008remove_zero_width_bit_fields (tree t) 4009{ 4010 tree *fieldsp; 4011 4012 fieldsp = &TYPE_FIELDS (t); 4013 while (*fieldsp) 4014 { 4015 if (TREE_CODE (*fieldsp) == FIELD_DECL 4016 && DECL_C_BIT_FIELD (*fieldsp) 4017 && DECL_INITIAL (*fieldsp)) 4018 *fieldsp = TREE_CHAIN (*fieldsp); 4019 else 4020 fieldsp = &TREE_CHAIN (*fieldsp); 4021 } 4022} 4023 4024/* Returns TRUE iff we need a cookie when dynamically allocating an 4025 array whose elements have the indicated class TYPE. */ 4026 4027static bool 4028type_requires_array_cookie (tree type) 4029{ 4030 tree fns; 4031 bool has_two_argument_delete_p = false; 4032 4033 gcc_assert (CLASS_TYPE_P (type)); 4034 4035 /* If there's a non-trivial destructor, we need a cookie. In order 4036 to iterate through the array calling the destructor for each 4037 element, we'll have to know how many elements there are. */ 4038 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) 4039 return true; 4040 4041 /* If the usual deallocation function is a two-argument whose second 4042 argument is of type `size_t', then we have to pass the size of 4043 the array to the deallocation function, so we will need to store 4044 a cookie. */ 4045 fns = lookup_fnfields (TYPE_BINFO (type), 4046 ansi_opname (VEC_DELETE_EXPR), 4047 /*protect=*/0); 4048 /* If there are no `operator []' members, or the lookup is 4049 ambiguous, then we don't need a cookie. */ 4050 if (!fns || fns == error_mark_node) 4051 return false; 4052 /* Loop through all of the functions. */ 4053 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns)) 4054 { 4055 tree fn; 4056 tree second_parm; 4057 4058 /* Select the current function. */ 4059 fn = OVL_CURRENT (fns); 4060 /* See if this function is a one-argument delete function. If 4061 it is, then it will be the usual deallocation function. */ 4062 second_parm = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (fn))); 4063 if (second_parm == void_list_node) 4064 return false; 4065 /* Otherwise, if we have a two-argument function and the second 4066 argument is `size_t', it will be the usual deallocation 4067 function -- unless there is one-argument function, too. */ 4068 if (TREE_CHAIN (second_parm) == void_list_node 4069 && same_type_p (TREE_VALUE (second_parm), sizetype)) 4070 has_two_argument_delete_p = true; 4071 } 4072 4073 return has_two_argument_delete_p; 4074} 4075 4076/* Check the validity of the bases and members declared in T. Add any 4077 implicitly-generated functions (like copy-constructors and 4078 assignment operators). Compute various flag bits (like 4079 CLASSTYPE_NON_POD_T) for T. This routine works purely at the C++ 4080 level: i.e., independently of the ABI in use. */ 4081 4082static void 4083check_bases_and_members (tree t) 4084{ 4085 /* Nonzero if the implicitly generated copy constructor should take 4086 a non-const reference argument. */ 4087 int cant_have_const_ctor; 4088 /* Nonzero if the implicitly generated assignment operator 4089 should take a non-const reference argument. */ 4090 int no_const_asn_ref; 4091 tree access_decls; 4092 4093 /* By default, we use const reference arguments and generate default 4094 constructors. */ 4095 cant_have_const_ctor = 0; 4096 no_const_asn_ref = 0; 4097 4098 /* Check all the base-classes. */ 4099 check_bases (t, &cant_have_const_ctor, 4100 &no_const_asn_ref); 4101 4102 /* Check all the method declarations. */ 4103 check_methods (t); 4104 4105 /* Check all the data member declarations. We cannot call 4106 check_field_decls until we have called check_bases check_methods, 4107 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR 4108 being set appropriately. */ 4109 check_field_decls (t, &access_decls, 4110 &cant_have_const_ctor, 4111 &no_const_asn_ref); 4112 4113 /* A nearly-empty class has to be vptr-containing; a nearly empty 4114 class contains just a vptr. */ 4115 if (!TYPE_CONTAINS_VPTR_P (t)) 4116 CLASSTYPE_NEARLY_EMPTY_P (t) = 0; 4117 4118 /* Do some bookkeeping that will guide the generation of implicitly 4119 declared member functions. */ 4120 TYPE_HAS_COMPLEX_INIT_REF (t) 4121 |= (TYPE_HAS_INIT_REF (t) || TYPE_CONTAINS_VPTR_P (t)); 4122 TYPE_NEEDS_CONSTRUCTING (t) 4123 |= (TYPE_HAS_CONSTRUCTOR (t) || TYPE_CONTAINS_VPTR_P (t)); 4124 CLASSTYPE_NON_AGGREGATE (t) 4125 |= (TYPE_HAS_CONSTRUCTOR (t) || TYPE_POLYMORPHIC_P (t)); 4126 CLASSTYPE_NON_POD_P (t) 4127 |= (CLASSTYPE_NON_AGGREGATE (t) 4128 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) 4129 || TYPE_HAS_ASSIGN_REF (t)); 4130 TYPE_HAS_COMPLEX_ASSIGN_REF (t) 4131 |= TYPE_HAS_ASSIGN_REF (t) || TYPE_CONTAINS_VPTR_P (t); 4132 4133 /* Synthesize any needed methods. */ 4134 add_implicitly_declared_members (t, 4135 cant_have_const_ctor, 4136 no_const_asn_ref); 4137 4138 /* Create the in-charge and not-in-charge variants of constructors 4139 and destructors. */ 4140 clone_constructors_and_destructors (t); 4141 4142 /* Process the using-declarations. */ 4143 for (; access_decls; access_decls = TREE_CHAIN (access_decls)) 4144 handle_using_decl (TREE_VALUE (access_decls), t); 4145 4146 /* Build and sort the CLASSTYPE_METHOD_VEC. */ 4147 finish_struct_methods (t); 4148 4149 /* Figure out whether or not we will need a cookie when dynamically 4150 allocating an array of this type. */ 4151 TYPE_LANG_SPECIFIC (t)->u.c.vec_new_uses_cookie 4152 = type_requires_array_cookie (t); 4153} 4154 4155/* If T needs a pointer to its virtual function table, set TYPE_VFIELD 4156 accordingly. If a new vfield was created (because T doesn't have a 4157 primary base class), then the newly created field is returned. It 4158 is not added to the TYPE_FIELDS list; it is the caller's 4159 responsibility to do that. Accumulate declared virtual functions 4160 on VIRTUALS_P. */ 4161 4162static tree 4163create_vtable_ptr (tree t, tree* virtuals_p) 4164{ 4165 tree fn; 4166 4167 /* Collect the virtual functions declared in T. */ 4168 for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn)) 4169 if (DECL_VINDEX (fn) && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn) 4170 && TREE_CODE (DECL_VINDEX (fn)) != INTEGER_CST) 4171 { 4172 tree new_virtual = make_node (TREE_LIST); 4173 4174 BV_FN (new_virtual) = fn; 4175 BV_DELTA (new_virtual) = integer_zero_node; 4176 BV_VCALL_INDEX (new_virtual) = NULL_TREE; 4177 4178 TREE_CHAIN (new_virtual) = *virtuals_p; 4179 *virtuals_p = new_virtual; 4180 } 4181 4182 /* If we couldn't find an appropriate base class, create a new field 4183 here. Even if there weren't any new virtual functions, we might need a 4184 new virtual function table if we're supposed to include vptrs in 4185 all classes that need them. */ 4186 if (!TYPE_VFIELD (t) && (*virtuals_p || TYPE_CONTAINS_VPTR_P (t))) 4187 { 4188 /* We build this decl with vtbl_ptr_type_node, which is a 4189 `vtable_entry_type*'. It might seem more precise to use 4190 `vtable_entry_type (*)[N]' where N is the number of virtual 4191 functions. However, that would require the vtable pointer in 4192 base classes to have a different type than the vtable pointer 4193 in derived classes. We could make that happen, but that 4194 still wouldn't solve all the problems. In particular, the 4195 type-based alias analysis code would decide that assignments 4196 to the base class vtable pointer can't alias assignments to 4197 the derived class vtable pointer, since they have different 4198 types. Thus, in a derived class destructor, where the base 4199 class constructor was inlined, we could generate bad code for 4200 setting up the vtable pointer. 4201 4202 Therefore, we use one type for all vtable pointers. We still 4203 use a type-correct type; it's just doesn't indicate the array 4204 bounds. That's better than using `void*' or some such; it's 4205 cleaner, and it let's the alias analysis code know that these 4206 stores cannot alias stores to void*! */ 4207 tree field; 4208 4209 field = build_decl (FIELD_DECL, get_vfield_name (t), vtbl_ptr_type_node); 4210 DECL_VIRTUAL_P (field) = 1; 4211 DECL_ARTIFICIAL (field) = 1; 4212 DECL_FIELD_CONTEXT (field) = t; 4213 DECL_FCONTEXT (field) = t; 4214 4215 TYPE_VFIELD (t) = field; 4216 4217 /* This class is non-empty. */ 4218 CLASSTYPE_EMPTY_P (t) = 0; 4219 4220 return field; 4221 } 4222 4223 return NULL_TREE; 4224} 4225 4226/* Fixup the inline function given by INFO now that the class is 4227 complete. */ 4228 4229static void 4230fixup_pending_inline (tree fn) 4231{ 4232 if (DECL_PENDING_INLINE_INFO (fn)) 4233 { 4234 tree args = DECL_ARGUMENTS (fn); 4235 while (args) 4236 { 4237 DECL_CONTEXT (args) = fn; 4238 args = TREE_CHAIN (args); 4239 } 4240 } 4241} 4242 4243/* Fixup the inline methods and friends in TYPE now that TYPE is 4244 complete. */ 4245 4246static void 4247fixup_inline_methods (tree type) 4248{ 4249 tree method = TYPE_METHODS (type); 4250 VEC(tree,gc) *friends; 4251 unsigned ix; 4252 4253 if (method && TREE_CODE (method) == TREE_VEC) 4254 { 4255 if (TREE_VEC_ELT (method, 1)) 4256 method = TREE_VEC_ELT (method, 1); 4257 else if (TREE_VEC_ELT (method, 0)) 4258 method = TREE_VEC_ELT (method, 0); 4259 else 4260 method = TREE_VEC_ELT (method, 2); 4261 } 4262 4263 /* Do inline member functions. */ 4264 for (; method; method = TREE_CHAIN (method)) 4265 fixup_pending_inline (method); 4266 4267 /* Do friends. */ 4268 for (friends = CLASSTYPE_INLINE_FRIENDS (type), ix = 0; 4269 VEC_iterate (tree, friends, ix, method); ix++) 4270 fixup_pending_inline (method); 4271 CLASSTYPE_INLINE_FRIENDS (type) = NULL; 4272} 4273 4274/* Add OFFSET to all base types of BINFO which is a base in the 4275 hierarchy dominated by T. 4276 4277 OFFSET, which is a type offset, is number of bytes. */ 4278 4279static void 4280propagate_binfo_offsets (tree binfo, tree offset) 4281{ 4282 int i; 4283 tree primary_binfo; 4284 tree base_binfo; 4285 4286 /* Update BINFO's offset. */ 4287 BINFO_OFFSET (binfo) 4288 = convert (sizetype, 4289 size_binop (PLUS_EXPR, 4290 convert (ssizetype, BINFO_OFFSET (binfo)), 4291 offset)); 4292 4293 /* Find the primary base class. */ 4294 primary_binfo = get_primary_binfo (binfo); 4295 4296 if (primary_binfo && BINFO_INHERITANCE_CHAIN (primary_binfo) == binfo) 4297 propagate_binfo_offsets (primary_binfo, offset); 4298 4299 /* Scan all of the bases, pushing the BINFO_OFFSET adjust 4300 downwards. */ 4301 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 4302 { 4303 /* Don't do the primary base twice. */ 4304 if (base_binfo == primary_binfo) 4305 continue; 4306 4307 if (BINFO_VIRTUAL_P (base_binfo)) 4308 continue; 4309 4310 propagate_binfo_offsets (base_binfo, offset); 4311 } 4312} 4313 4314/* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update 4315 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of 4316 empty subobjects of T. */ 4317 4318static void 4319layout_virtual_bases (record_layout_info rli, splay_tree offsets) 4320{ 4321 tree vbase; 4322 tree t = rli->t; 4323 bool first_vbase = true; 4324 tree *next_field; 4325 4326 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) == 0) 4327 return; 4328 4329 if (!abi_version_at_least(2)) 4330 { 4331 /* In G++ 3.2, we incorrectly rounded the size before laying out 4332 the virtual bases. */ 4333 finish_record_layout (rli, /*free_p=*/false); 4334#ifdef STRUCTURE_SIZE_BOUNDARY 4335 /* Packed structures don't need to have minimum size. */ 4336 if (! TYPE_PACKED (t)) 4337 TYPE_ALIGN (t) = MAX (TYPE_ALIGN (t), (unsigned) STRUCTURE_SIZE_BOUNDARY); 4338#endif 4339 rli->offset = TYPE_SIZE_UNIT (t); 4340 rli->bitpos = bitsize_zero_node; 4341 rli->record_align = TYPE_ALIGN (t); 4342 } 4343 4344 /* Find the last field. The artificial fields created for virtual 4345 bases will go after the last extant field to date. */ 4346 next_field = &TYPE_FIELDS (t); 4347 while (*next_field) 4348 next_field = &TREE_CHAIN (*next_field); 4349 4350 /* Go through the virtual bases, allocating space for each virtual 4351 base that is not already a primary base class. These are 4352 allocated in inheritance graph order. */ 4353 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase)) 4354 { 4355 if (!BINFO_VIRTUAL_P (vbase)) 4356 continue; 4357 4358 if (!BINFO_PRIMARY_P (vbase)) 4359 { 4360 tree basetype = TREE_TYPE (vbase); 4361 4362 /* This virtual base is not a primary base of any class in the 4363 hierarchy, so we have to add space for it. */ 4364 next_field = build_base_field (rli, vbase, 4365 offsets, next_field); 4366 4367 /* If the first virtual base might have been placed at a 4368 lower address, had we started from CLASSTYPE_SIZE, rather 4369 than TYPE_SIZE, issue a warning. There can be both false 4370 positives and false negatives from this warning in rare 4371 cases; to deal with all the possibilities would probably 4372 require performing both layout algorithms and comparing 4373 the results which is not particularly tractable. */ 4374 if (warn_abi 4375 && first_vbase 4376 && (tree_int_cst_lt 4377 (size_binop (CEIL_DIV_EXPR, 4378 round_up (CLASSTYPE_SIZE (t), 4379 CLASSTYPE_ALIGN (basetype)), 4380 bitsize_unit_node), 4381 BINFO_OFFSET (vbase)))) 4382 warning (0, "offset of virtual base %qT is not ABI-compliant and " 4383 "may change in a future version of GCC", 4384 basetype); 4385 4386 first_vbase = false; 4387 } 4388 } 4389} 4390 4391/* Returns the offset of the byte just past the end of the base class 4392 BINFO. */ 4393 4394static tree 4395end_of_base (tree binfo) 4396{ 4397 tree size; 4398 4399 if (is_empty_class (BINFO_TYPE (binfo))) 4400 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to 4401 allocate some space for it. It cannot have virtual bases, so 4402 TYPE_SIZE_UNIT is fine. */ 4403 size = TYPE_SIZE_UNIT (BINFO_TYPE (binfo)); 4404 else 4405 size = CLASSTYPE_SIZE_UNIT (BINFO_TYPE (binfo)); 4406 4407 return size_binop (PLUS_EXPR, BINFO_OFFSET (binfo), size); 4408} 4409 4410/* Returns the offset of the byte just past the end of the base class 4411 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then 4412 only non-virtual bases are included. */ 4413 4414static tree 4415end_of_class (tree t, int include_virtuals_p) 4416{ 4417 tree result = size_zero_node; 4418 VEC(tree,gc) *vbases; 4419 tree binfo; 4420 tree base_binfo; 4421 tree offset; 4422 int i; 4423 4424 for (binfo = TYPE_BINFO (t), i = 0; 4425 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 4426 { 4427 if (!include_virtuals_p 4428 && BINFO_VIRTUAL_P (base_binfo) 4429 && (!BINFO_PRIMARY_P (base_binfo) 4430 || BINFO_INHERITANCE_CHAIN (base_binfo) != TYPE_BINFO (t))) 4431 continue; 4432 4433 offset = end_of_base (base_binfo); 4434 if (INT_CST_LT_UNSIGNED (result, offset)) 4435 result = offset; 4436 } 4437 4438 /* G++ 3.2 did not check indirect virtual bases. */ 4439 if (abi_version_at_least (2) && include_virtuals_p) 4440 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0; 4441 VEC_iterate (tree, vbases, i, base_binfo); i++) 4442 { 4443 offset = end_of_base (base_binfo); 4444 if (INT_CST_LT_UNSIGNED (result, offset)) 4445 result = offset; 4446 } 4447 4448 return result; 4449} 4450 4451/* Warn about bases of T that are inaccessible because they are 4452 ambiguous. For example: 4453 4454 struct S {}; 4455 struct T : public S {}; 4456 struct U : public S, public T {}; 4457 4458 Here, `(S*) new U' is not allowed because there are two `S' 4459 subobjects of U. */ 4460 4461static void 4462warn_about_ambiguous_bases (tree t) 4463{ 4464 int i; 4465 VEC(tree,gc) *vbases; 4466 tree basetype; 4467 tree binfo; 4468 tree base_binfo; 4469 4470 /* If there are no repeated bases, nothing can be ambiguous. */ 4471 if (!CLASSTYPE_REPEATED_BASE_P (t)) 4472 return; 4473 4474 /* Check direct bases. */ 4475 for (binfo = TYPE_BINFO (t), i = 0; 4476 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 4477 { 4478 basetype = BINFO_TYPE (base_binfo); 4479 4480 if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL)) 4481 warning (0, "direct base %qT inaccessible in %qT due to ambiguity", 4482 basetype, t); 4483 } 4484 4485 /* Check for ambiguous virtual bases. */ 4486 if (extra_warnings) 4487 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0; 4488 VEC_iterate (tree, vbases, i, binfo); i++) 4489 { 4490 basetype = BINFO_TYPE (binfo); 4491 4492 if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL)) 4493 warning (0, "virtual base %qT inaccessible in %qT due to ambiguity", 4494 basetype, t); 4495 } 4496} 4497 4498/* Compare two INTEGER_CSTs K1 and K2. */ 4499 4500static int 4501splay_tree_compare_integer_csts (splay_tree_key k1, splay_tree_key k2) 4502{ 4503 return tree_int_cst_compare ((tree) k1, (tree) k2); 4504} 4505 4506/* Increase the size indicated in RLI to account for empty classes 4507 that are "off the end" of the class. */ 4508 4509static void 4510include_empty_classes (record_layout_info rli) 4511{ 4512 tree eoc; 4513 tree rli_size; 4514 4515 /* It might be the case that we grew the class to allocate a 4516 zero-sized base class. That won't be reflected in RLI, yet, 4517 because we are willing to overlay multiple bases at the same 4518 offset. However, now we need to make sure that RLI is big enough 4519 to reflect the entire class. */ 4520 eoc = end_of_class (rli->t, 4521 CLASSTYPE_AS_BASE (rli->t) != NULL_TREE); 4522 rli_size = rli_size_unit_so_far (rli); 4523 if (TREE_CODE (rli_size) == INTEGER_CST 4524 && INT_CST_LT_UNSIGNED (rli_size, eoc)) 4525 { 4526 if (!abi_version_at_least (2)) 4527 /* In version 1 of the ABI, the size of a class that ends with 4528 a bitfield was not rounded up to a whole multiple of a 4529 byte. Because rli_size_unit_so_far returns only the number 4530 of fully allocated bytes, any extra bits were not included 4531 in the size. */ 4532 rli->bitpos = round_down (rli->bitpos, BITS_PER_UNIT); 4533 else 4534 /* The size should have been rounded to a whole byte. */ 4535 gcc_assert (tree_int_cst_equal 4536 (rli->bitpos, round_down (rli->bitpos, BITS_PER_UNIT))); 4537 rli->bitpos 4538 = size_binop (PLUS_EXPR, 4539 rli->bitpos, 4540 size_binop (MULT_EXPR, 4541 convert (bitsizetype, 4542 size_binop (MINUS_EXPR, 4543 eoc, rli_size)), 4544 bitsize_int (BITS_PER_UNIT))); 4545 normalize_rli (rli); 4546 } 4547} 4548 4549/* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate 4550 BINFO_OFFSETs for all of the base-classes. Position the vtable 4551 pointer. Accumulate declared virtual functions on VIRTUALS_P. */ 4552 4553static void 4554layout_class_type (tree t, tree *virtuals_p) 4555{ 4556 tree non_static_data_members; 4557 tree field; 4558 tree vptr; 4559 record_layout_info rli; 4560 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of 4561 types that appear at that offset. */ 4562 splay_tree empty_base_offsets; 4563 /* True if the last field layed out was a bit-field. */ 4564 bool last_field_was_bitfield = false; 4565 /* The location at which the next field should be inserted. */ 4566 tree *next_field; 4567 /* T, as a base class. */ 4568 tree base_t; 4569 4570 /* Keep track of the first non-static data member. */ 4571 non_static_data_members = TYPE_FIELDS (t); 4572 4573 /* Start laying out the record. */ 4574 rli = start_record_layout (t); 4575 4576 /* Mark all the primary bases in the hierarchy. */ 4577 determine_primary_bases (t); 4578 4579 /* Create a pointer to our virtual function table. */ 4580 vptr = create_vtable_ptr (t, virtuals_p); 4581 4582 /* The vptr is always the first thing in the class. */ 4583 if (vptr) 4584 { 4585 TREE_CHAIN (vptr) = TYPE_FIELDS (t); 4586 TYPE_FIELDS (t) = vptr; 4587 next_field = &TREE_CHAIN (vptr); 4588 place_field (rli, vptr); 4589 } 4590 else 4591 next_field = &TYPE_FIELDS (t); 4592 4593 /* Build FIELD_DECLs for all of the non-virtual base-types. */ 4594 empty_base_offsets = splay_tree_new (splay_tree_compare_integer_csts, 4595 NULL, NULL); 4596 build_base_fields (rli, empty_base_offsets, next_field); 4597 4598 /* Layout the non-static data members. */ 4599 for (field = non_static_data_members; field; field = TREE_CHAIN (field)) 4600 { 4601 tree type; 4602 tree padding; 4603 4604 /* We still pass things that aren't non-static data members to 4605 the back-end, in case it wants to do something with them. */ 4606 if (TREE_CODE (field) != FIELD_DECL) 4607 { 4608 place_field (rli, field); 4609 /* If the static data member has incomplete type, keep track 4610 of it so that it can be completed later. (The handling 4611 of pending statics in finish_record_layout is 4612 insufficient; consider: 4613 4614 struct S1; 4615 struct S2 { static S1 s1; }; 4616 4617 At this point, finish_record_layout will be called, but 4618 S1 is still incomplete.) */ 4619 if (TREE_CODE (field) == VAR_DECL) 4620 { 4621 maybe_register_incomplete_var (field); 4622 /* The visibility of static data members is determined 4623 at their point of declaration, not their point of 4624 definition. */ 4625 determine_visibility (field); 4626 } 4627 continue; 4628 } 4629 4630 type = TREE_TYPE (field); 4631 4632 padding = NULL_TREE; 4633 4634 /* If this field is a bit-field whose width is greater than its 4635 type, then there are some special rules for allocating 4636 it. */ 4637 if (DECL_C_BIT_FIELD (field) 4638 && INT_CST_LT (TYPE_SIZE (type), DECL_SIZE (field))) 4639 { 4640 integer_type_kind itk; 4641 tree integer_type; 4642 bool was_unnamed_p = false; 4643 /* We must allocate the bits as if suitably aligned for the 4644 longest integer type that fits in this many bits. type 4645 of the field. Then, we are supposed to use the left over 4646 bits as additional padding. */ 4647 for (itk = itk_char; itk != itk_none; ++itk) 4648 if (INT_CST_LT (DECL_SIZE (field), 4649 TYPE_SIZE (integer_types[itk]))) 4650 break; 4651 4652 /* ITK now indicates a type that is too large for the 4653 field. We have to back up by one to find the largest 4654 type that fits. */ 4655 integer_type = integer_types[itk - 1]; 4656 4657 /* Figure out how much additional padding is required. GCC 4658 3.2 always created a padding field, even if it had zero 4659 width. */ 4660 if (!abi_version_at_least (2) 4661 || INT_CST_LT (TYPE_SIZE (integer_type), DECL_SIZE (field))) 4662 { 4663 if (abi_version_at_least (2) && TREE_CODE (t) == UNION_TYPE) 4664 /* In a union, the padding field must have the full width 4665 of the bit-field; all fields start at offset zero. */ 4666 padding = DECL_SIZE (field); 4667 else 4668 { 4669 if (warn_abi && TREE_CODE (t) == UNION_TYPE) 4670 warning (0, "size assigned to %qT may not be " 4671 "ABI-compliant and may change in a future " 4672 "version of GCC", 4673 t); 4674 padding = size_binop (MINUS_EXPR, DECL_SIZE (field), 4675 TYPE_SIZE (integer_type)); 4676 } 4677 } 4678#ifdef PCC_BITFIELD_TYPE_MATTERS 4679 /* An unnamed bitfield does not normally affect the 4680 alignment of the containing class on a target where 4681 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not 4682 make any exceptions for unnamed bitfields when the 4683 bitfields are longer than their types. Therefore, we 4684 temporarily give the field a name. */ 4685 if (PCC_BITFIELD_TYPE_MATTERS && !DECL_NAME (field)) 4686 { 4687 was_unnamed_p = true; 4688 DECL_NAME (field) = make_anon_name (); 4689 } 4690#endif 4691 DECL_SIZE (field) = TYPE_SIZE (integer_type); 4692 DECL_ALIGN (field) = TYPE_ALIGN (integer_type); 4693 DECL_USER_ALIGN (field) = TYPE_USER_ALIGN (integer_type); 4694 layout_nonempty_base_or_field (rli, field, NULL_TREE, 4695 empty_base_offsets); 4696 if (was_unnamed_p) 4697 DECL_NAME (field) = NULL_TREE; 4698 /* Now that layout has been performed, set the size of the 4699 field to the size of its declared type; the rest of the 4700 field is effectively invisible. */ 4701 DECL_SIZE (field) = TYPE_SIZE (type); 4702 /* We must also reset the DECL_MODE of the field. */ 4703 if (abi_version_at_least (2)) 4704 DECL_MODE (field) = TYPE_MODE (type); 4705 else if (warn_abi 4706 && DECL_MODE (field) != TYPE_MODE (type)) 4707 /* Versions of G++ before G++ 3.4 did not reset the 4708 DECL_MODE. */ 4709 warning (0, "the offset of %qD may not be ABI-compliant and may " 4710 "change in a future version of GCC", field); 4711 } 4712 else 4713 layout_nonempty_base_or_field (rli, field, NULL_TREE, 4714 empty_base_offsets); 4715 4716 /* Remember the location of any empty classes in FIELD. */ 4717 if (abi_version_at_least (2)) 4718 record_subobject_offsets (TREE_TYPE (field), 4719 byte_position(field), 4720 empty_base_offsets, 4721 /*is_data_member=*/true); 4722 4723 /* If a bit-field does not immediately follow another bit-field, 4724 and yet it starts in the middle of a byte, we have failed to 4725 comply with the ABI. */ 4726 if (warn_abi 4727 && DECL_C_BIT_FIELD (field) 4728 /* The TREE_NO_WARNING flag gets set by Objective-C when 4729 laying out an Objective-C class. The ObjC ABI differs 4730 from the C++ ABI, and so we do not want a warning 4731 here. */ 4732 && !TREE_NO_WARNING (field) 4733 && !last_field_was_bitfield 4734 && !integer_zerop (size_binop (TRUNC_MOD_EXPR, 4735 DECL_FIELD_BIT_OFFSET (field), 4736 bitsize_unit_node))) 4737 warning (0, "offset of %q+D is not ABI-compliant and may " 4738 "change in a future version of GCC", field); 4739 4740 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte 4741 offset of the field. */ 4742 if (warn_abi 4743 && !tree_int_cst_equal (DECL_FIELD_OFFSET (field), 4744 byte_position (field)) 4745 && contains_empty_class_p (TREE_TYPE (field))) 4746 warning (0, "%q+D contains empty classes which may cause base " 4747 "classes to be placed at different locations in a " 4748 "future version of GCC", field); 4749 4750 /* If we needed additional padding after this field, add it 4751 now. */ 4752 if (padding) 4753 { 4754 tree padding_field; 4755 4756 padding_field = build_decl (FIELD_DECL, 4757 NULL_TREE, 4758 char_type_node); 4759 DECL_BIT_FIELD (padding_field) = 1; 4760 DECL_SIZE (padding_field) = padding; 4761 DECL_CONTEXT (padding_field) = t; 4762 DECL_ARTIFICIAL (padding_field) = 1; 4763 DECL_IGNORED_P (padding_field) = 1; 4764 layout_nonempty_base_or_field (rli, padding_field, 4765 NULL_TREE, 4766 empty_base_offsets); 4767 } 4768 4769 last_field_was_bitfield = DECL_C_BIT_FIELD (field); 4770 } 4771 4772 if (abi_version_at_least (2) && !integer_zerop (rli->bitpos)) 4773 { 4774 /* Make sure that we are on a byte boundary so that the size of 4775 the class without virtual bases will always be a round number 4776 of bytes. */ 4777 rli->bitpos = round_up (rli->bitpos, BITS_PER_UNIT); 4778 normalize_rli (rli); 4779 } 4780 4781 /* G++ 3.2 does not allow virtual bases to be overlaid with tail 4782 padding. */ 4783 if (!abi_version_at_least (2)) 4784 include_empty_classes(rli); 4785 4786 /* Delete all zero-width bit-fields from the list of fields. Now 4787 that the type is laid out they are no longer important. */ 4788 remove_zero_width_bit_fields (t); 4789 4790 /* Create the version of T used for virtual bases. We do not use 4791 make_aggr_type for this version; this is an artificial type. For 4792 a POD type, we just reuse T. */ 4793 if (CLASSTYPE_NON_POD_P (t) || CLASSTYPE_EMPTY_P (t)) 4794 { 4795 base_t = make_node (TREE_CODE (t)); 4796 4797 /* Set the size and alignment for the new type. In G++ 3.2, all 4798 empty classes were considered to have size zero when used as 4799 base classes. */ 4800 if (!abi_version_at_least (2) && CLASSTYPE_EMPTY_P (t)) 4801 { 4802 TYPE_SIZE (base_t) = bitsize_zero_node; 4803 TYPE_SIZE_UNIT (base_t) = size_zero_node; 4804 if (warn_abi && !integer_zerop (rli_size_unit_so_far (rli))) 4805 warning (0, "layout of classes derived from empty class %qT " 4806 "may change in a future version of GCC", 4807 t); 4808 } 4809 else 4810 { 4811 tree eoc; 4812 4813 /* If the ABI version is not at least two, and the last 4814 field was a bit-field, RLI may not be on a byte 4815 boundary. In particular, rli_size_unit_so_far might 4816 indicate the last complete byte, while rli_size_so_far 4817 indicates the total number of bits used. Therefore, 4818 rli_size_so_far, rather than rli_size_unit_so_far, is 4819 used to compute TYPE_SIZE_UNIT. */ 4820 eoc = end_of_class (t, /*include_virtuals_p=*/0); 4821 TYPE_SIZE_UNIT (base_t) 4822 = size_binop (MAX_EXPR, 4823 convert (sizetype, 4824 size_binop (CEIL_DIV_EXPR, 4825 rli_size_so_far (rli), 4826 bitsize_int (BITS_PER_UNIT))), 4827 eoc); 4828 TYPE_SIZE (base_t) 4829 = size_binop (MAX_EXPR, 4830 rli_size_so_far (rli), 4831 size_binop (MULT_EXPR, 4832 convert (bitsizetype, eoc), 4833 bitsize_int (BITS_PER_UNIT))); 4834 } 4835 TYPE_ALIGN (base_t) = rli->record_align; 4836 TYPE_USER_ALIGN (base_t) = TYPE_USER_ALIGN (t); 4837 4838 /* Copy the fields from T. */ 4839 next_field = &TYPE_FIELDS (base_t); 4840 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field)) 4841 if (TREE_CODE (field) == FIELD_DECL) 4842 { 4843 *next_field = build_decl (FIELD_DECL, 4844 DECL_NAME (field), 4845 TREE_TYPE (field)); 4846 DECL_CONTEXT (*next_field) = base_t; 4847 DECL_FIELD_OFFSET (*next_field) = DECL_FIELD_OFFSET (field); 4848 DECL_FIELD_BIT_OFFSET (*next_field) 4849 = DECL_FIELD_BIT_OFFSET (field); 4850 DECL_SIZE (*next_field) = DECL_SIZE (field); 4851 DECL_MODE (*next_field) = DECL_MODE (field); 4852 next_field = &TREE_CHAIN (*next_field); 4853 } 4854 4855 /* Record the base version of the type. */ 4856 CLASSTYPE_AS_BASE (t) = base_t; 4857 TYPE_CONTEXT (base_t) = t; 4858 } 4859 else 4860 CLASSTYPE_AS_BASE (t) = t; 4861 4862 /* Every empty class contains an empty class. */ 4863 if (CLASSTYPE_EMPTY_P (t)) 4864 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1; 4865 4866 /* Set the TYPE_DECL for this type to contain the right 4867 value for DECL_OFFSET, so that we can use it as part 4868 of a COMPONENT_REF for multiple inheritance. */ 4869 layout_decl (TYPE_MAIN_DECL (t), 0); 4870 4871 /* Now fix up any virtual base class types that we left lying 4872 around. We must get these done before we try to lay out the 4873 virtual function table. As a side-effect, this will remove the 4874 base subobject fields. */ 4875 layout_virtual_bases (rli, empty_base_offsets); 4876 4877 /* Make sure that empty classes are reflected in RLI at this 4878 point. */ 4879 include_empty_classes(rli); 4880 4881 /* Make sure not to create any structures with zero size. */ 4882 if (integer_zerop (rli_size_unit_so_far (rli)) && CLASSTYPE_EMPTY_P (t)) 4883 place_field (rli, 4884 build_decl (FIELD_DECL, NULL_TREE, char_type_node)); 4885 4886 /* Let the back-end lay out the type. */ 4887 finish_record_layout (rli, /*free_p=*/true); 4888 4889 /* Warn about bases that can't be talked about due to ambiguity. */ 4890 warn_about_ambiguous_bases (t); 4891 4892 /* Now that we're done with layout, give the base fields the real types. */ 4893 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field)) 4894 if (DECL_ARTIFICIAL (field) && IS_FAKE_BASE_TYPE (TREE_TYPE (field))) 4895 TREE_TYPE (field) = TYPE_CONTEXT (TREE_TYPE (field)); 4896 4897 /* Clean up. */ 4898 splay_tree_delete (empty_base_offsets); 4899 4900 if (CLASSTYPE_EMPTY_P (t) 4901 && tree_int_cst_lt (sizeof_biggest_empty_class, 4902 TYPE_SIZE_UNIT (t))) 4903 sizeof_biggest_empty_class = TYPE_SIZE_UNIT (t); 4904} 4905 4906/* Determine the "key method" for the class type indicated by TYPE, 4907 and set CLASSTYPE_KEY_METHOD accordingly. */ 4908 4909void 4910determine_key_method (tree type) 4911{ 4912 tree method; 4913 4914 if (TYPE_FOR_JAVA (type) 4915 || processing_template_decl 4916 || CLASSTYPE_TEMPLATE_INSTANTIATION (type) 4917 || CLASSTYPE_INTERFACE_KNOWN (type)) 4918 return; 4919 4920 /* The key method is the first non-pure virtual function that is not 4921 inline at the point of class definition. On some targets the 4922 key function may not be inline; those targets should not call 4923 this function until the end of the translation unit. */ 4924 for (method = TYPE_METHODS (type); method != NULL_TREE; 4925 method = TREE_CHAIN (method)) 4926 if (DECL_VINDEX (method) != NULL_TREE 4927 && ! DECL_DECLARED_INLINE_P (method) 4928 && ! DECL_PURE_VIRTUAL_P (method)) 4929 { 4930 CLASSTYPE_KEY_METHOD (type) = method; 4931 break; 4932 } 4933 4934 return; 4935} 4936 4937/* Perform processing required when the definition of T (a class type) 4938 is complete. */ 4939 4940void 4941finish_struct_1 (tree t) 4942{ 4943 tree x; 4944 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */ 4945 tree virtuals = NULL_TREE; 4946 int n_fields = 0; 4947 4948 if (COMPLETE_TYPE_P (t)) 4949 { 4950 gcc_assert (IS_AGGR_TYPE (t)); 4951 error ("redefinition of %q#T", t); 4952 popclass (); 4953 return; 4954 } 4955 4956 /* If this type was previously laid out as a forward reference, 4957 make sure we lay it out again. */ 4958 TYPE_SIZE (t) = NULL_TREE; 4959 CLASSTYPE_PRIMARY_BINFO (t) = NULL_TREE; 4960 4961 fixup_inline_methods (t); 4962 4963 /* Make assumptions about the class; we'll reset the flags if 4964 necessary. */ 4965 CLASSTYPE_EMPTY_P (t) = 1; 4966 CLASSTYPE_NEARLY_EMPTY_P (t) = 1; 4967 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 0; 4968 4969 /* Do end-of-class semantic processing: checking the validity of the 4970 bases and members and add implicitly generated methods. */ 4971 check_bases_and_members (t); 4972 4973 /* Find the key method. */ 4974 if (TYPE_CONTAINS_VPTR_P (t)) 4975 { 4976 /* The Itanium C++ ABI permits the key method to be chosen when 4977 the class is defined -- even though the key method so 4978 selected may later turn out to be an inline function. On 4979 some systems (such as ARM Symbian OS) the key method cannot 4980 be determined until the end of the translation unit. On such 4981 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which 4982 will cause the class to be added to KEYED_CLASSES. Then, in 4983 finish_file we will determine the key method. */ 4984 if (targetm.cxx.key_method_may_be_inline ()) 4985 determine_key_method (t); 4986 4987 /* If a polymorphic class has no key method, we may emit the vtable 4988 in every translation unit where the class definition appears. */ 4989 if (CLASSTYPE_KEY_METHOD (t) == NULL_TREE) 4990 keyed_classes = tree_cons (NULL_TREE, t, keyed_classes); 4991 } 4992 4993 /* Layout the class itself. */ 4994 layout_class_type (t, &virtuals); 4995 if (CLASSTYPE_AS_BASE (t) != t) 4996 /* We use the base type for trivial assignments, and hence it 4997 needs a mode. */ 4998 compute_record_mode (CLASSTYPE_AS_BASE (t)); 4999 5000 virtuals = modify_all_vtables (t, nreverse (virtuals)); 5001 5002 /* If necessary, create the primary vtable for this class. */ 5003 if (virtuals || TYPE_CONTAINS_VPTR_P (t)) 5004 { 5005 /* We must enter these virtuals into the table. */ 5006 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 5007 build_primary_vtable (NULL_TREE, t); 5008 else if (! BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (t))) 5009 /* Here we know enough to change the type of our virtual 5010 function table, but we will wait until later this function. */ 5011 build_primary_vtable (CLASSTYPE_PRIMARY_BINFO (t), t); 5012 } 5013 5014 if (TYPE_CONTAINS_VPTR_P (t)) 5015 { 5016 int vindex; 5017 tree fn; 5018 5019 if (BINFO_VTABLE (TYPE_BINFO (t))) 5020 gcc_assert (DECL_VIRTUAL_P (BINFO_VTABLE (TYPE_BINFO (t)))); 5021 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t)) 5022 gcc_assert (BINFO_VIRTUALS (TYPE_BINFO (t)) == NULL_TREE); 5023 5024 /* Add entries for virtual functions introduced by this class. */ 5025 BINFO_VIRTUALS (TYPE_BINFO (t)) 5026 = chainon (BINFO_VIRTUALS (TYPE_BINFO (t)), virtuals); 5027 5028 /* Set DECL_VINDEX for all functions declared in this class. */ 5029 for (vindex = 0, fn = BINFO_VIRTUALS (TYPE_BINFO (t)); 5030 fn; 5031 fn = TREE_CHAIN (fn), 5032 vindex += (TARGET_VTABLE_USES_DESCRIPTORS 5033 ? TARGET_VTABLE_USES_DESCRIPTORS : 1)) 5034 { 5035 tree fndecl = BV_FN (fn); 5036 5037 if (DECL_THUNK_P (fndecl)) 5038 /* A thunk. We should never be calling this entry directly 5039 from this vtable -- we'd use the entry for the non 5040 thunk base function. */ 5041 DECL_VINDEX (fndecl) = NULL_TREE; 5042 else if (TREE_CODE (DECL_VINDEX (fndecl)) != INTEGER_CST) 5043 DECL_VINDEX (fndecl) = build_int_cst (NULL_TREE, vindex); 5044 } 5045 } 5046 5047 finish_struct_bits (t); 5048 5049 /* Complete the rtl for any static member objects of the type we're 5050 working on. */ 5051 for (x = TYPE_FIELDS (t); x; x = TREE_CHAIN (x)) 5052 if (TREE_CODE (x) == VAR_DECL && TREE_STATIC (x) 5053 && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (x)), t)) 5054 DECL_MODE (x) = TYPE_MODE (t); 5055 5056 /* Done with FIELDS...now decide whether to sort these for 5057 faster lookups later. 5058 5059 We use a small number because most searches fail (succeeding 5060 ultimately as the search bores through the inheritance 5061 hierarchy), and we want this failure to occur quickly. */ 5062 5063 n_fields = count_fields (TYPE_FIELDS (t)); 5064 if (n_fields > 7) 5065 { 5066 struct sorted_fields_type *field_vec = GGC_NEWVAR 5067 (struct sorted_fields_type, 5068 sizeof (struct sorted_fields_type) + n_fields * sizeof (tree)); 5069 field_vec->len = n_fields; 5070 add_fields_to_record_type (TYPE_FIELDS (t), field_vec, 0); 5071 qsort (field_vec->elts, n_fields, sizeof (tree), 5072 field_decl_cmp); 5073 if (! DECL_LANG_SPECIFIC (TYPE_MAIN_DECL (t))) 5074 retrofit_lang_decl (TYPE_MAIN_DECL (t)); 5075 DECL_SORTED_FIELDS (TYPE_MAIN_DECL (t)) = field_vec; 5076 } 5077 5078 /* Make the rtl for any new vtables we have created, and unmark 5079 the base types we marked. */ 5080 finish_vtbls (t); 5081 5082 /* Build the VTT for T. */ 5083 build_vtt (t); 5084 5085 /* This warning does not make sense for Java classes, since they 5086 cannot have destructors. */ 5087 if (!TYPE_FOR_JAVA (t) && warn_nonvdtor && TYPE_POLYMORPHIC_P (t)) 5088 { 5089 tree dtor; 5090 5091 dtor = CLASSTYPE_DESTRUCTORS (t); 5092 /* Warn only if the dtor is non-private or the class has 5093 friends. */ 5094 if (/* An implicitly declared destructor is always public. And, 5095 if it were virtual, we would have created it by now. */ 5096 !dtor 5097 || (!DECL_VINDEX (dtor) 5098 && (!TREE_PRIVATE (dtor) 5099 || CLASSTYPE_FRIEND_CLASSES (t) 5100 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t))))) 5101 warning (0, "%q#T has virtual functions but non-virtual destructor", 5102 t); 5103 } 5104 5105 complete_vars (t); 5106 5107 if (warn_overloaded_virtual) 5108 warn_hidden (t); 5109 5110 /* Class layout, assignment of virtual table slots, etc., is now 5111 complete. Give the back end a chance to tweak the visibility of 5112 the class or perform any other required target modifications. */ 5113 targetm.cxx.adjust_class_at_definition (t); 5114 5115 maybe_suppress_debug_info (t); 5116 5117 dump_class_hierarchy (t); 5118 5119 /* Finish debugging output for this type. */ 5120 rest_of_type_compilation (t, ! LOCAL_CLASS_P (t)); 5121} 5122 5123/* When T was built up, the member declarations were added in reverse 5124 order. Rearrange them to declaration order. */ 5125 5126void 5127unreverse_member_declarations (tree t) 5128{ 5129 tree next; 5130 tree prev; 5131 tree x; 5132 5133 /* The following lists are all in reverse order. Put them in 5134 declaration order now. */ 5135 TYPE_METHODS (t) = nreverse (TYPE_METHODS (t)); 5136 CLASSTYPE_DECL_LIST (t) = nreverse (CLASSTYPE_DECL_LIST (t)); 5137 5138 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in 5139 reverse order, so we can't just use nreverse. */ 5140 prev = NULL_TREE; 5141 for (x = TYPE_FIELDS (t); 5142 x && TREE_CODE (x) != TYPE_DECL; 5143 x = next) 5144 { 5145 next = TREE_CHAIN (x); 5146 TREE_CHAIN (x) = prev; 5147 prev = x; 5148 } 5149 if (prev) 5150 { 5151 TREE_CHAIN (TYPE_FIELDS (t)) = x; 5152 if (prev) 5153 TYPE_FIELDS (t) = prev; 5154 } 5155} 5156 5157tree 5158finish_struct (tree t, tree attributes) 5159{ 5160 location_t saved_loc = input_location; 5161 5162 /* Now that we've got all the field declarations, reverse everything 5163 as necessary. */ 5164 unreverse_member_declarations (t); 5165 5166 cplus_decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE); 5167 5168 /* Nadger the current location so that diagnostics point to the start of 5169 the struct, not the end. */ 5170 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (t)); 5171 5172 if (processing_template_decl) 5173 { 5174 tree x; 5175 5176 finish_struct_methods (t); 5177 TYPE_SIZE (t) = bitsize_zero_node; 5178 TYPE_SIZE_UNIT (t) = size_zero_node; 5179 5180 /* We need to emit an error message if this type was used as a parameter 5181 and it is an abstract type, even if it is a template. We construct 5182 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into 5183 account and we call complete_vars with this type, which will check 5184 the PARM_DECLS. Note that while the type is being defined, 5185 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends 5186 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */ 5187 CLASSTYPE_PURE_VIRTUALS (t) = NULL; 5188 for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x)) 5189 if (DECL_PURE_VIRTUAL_P (x)) 5190 VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x); 5191 complete_vars (t); 5192 } 5193 else 5194 finish_struct_1 (t); 5195 5196 input_location = saved_loc; 5197 5198 TYPE_BEING_DEFINED (t) = 0; 5199 5200 if (current_class_type) 5201 popclass (); 5202 else 5203 error ("trying to finish struct, but kicked out due to previous parse errors"); 5204 5205 if (processing_template_decl && at_function_scope_p ()) 5206 add_stmt (build_min (TAG_DEFN, t)); 5207 5208 return t; 5209} 5210 5211/* Return the dynamic type of INSTANCE, if known. 5212 Used to determine whether the virtual function table is needed 5213 or not. 5214 5215 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless 5216 of our knowledge of its type. *NONNULL should be initialized 5217 before this function is called. */ 5218 5219static tree 5220fixed_type_or_null (tree instance, int* nonnull, int* cdtorp) 5221{ 5222 switch (TREE_CODE (instance)) 5223 { 5224 case INDIRECT_REF: 5225 if (POINTER_TYPE_P (TREE_TYPE (instance))) 5226 return NULL_TREE; 5227 else 5228 return fixed_type_or_null (TREE_OPERAND (instance, 0), 5229 nonnull, cdtorp); 5230 5231 case CALL_EXPR: 5232 /* This is a call to a constructor, hence it's never zero. */ 5233 if (TREE_HAS_CONSTRUCTOR (instance)) 5234 { 5235 if (nonnull) 5236 *nonnull = 1; 5237 return TREE_TYPE (instance); 5238 } 5239 return NULL_TREE; 5240 5241 case SAVE_EXPR: 5242 /* This is a call to a constructor, hence it's never zero. */ 5243 if (TREE_HAS_CONSTRUCTOR (instance)) 5244 { 5245 if (nonnull) 5246 *nonnull = 1; 5247 return TREE_TYPE (instance); 5248 } 5249 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp); 5250 5251 case PLUS_EXPR: 5252 case MINUS_EXPR: 5253 if (TREE_CODE (TREE_OPERAND (instance, 0)) == ADDR_EXPR) 5254 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp); 5255 if (TREE_CODE (TREE_OPERAND (instance, 1)) == INTEGER_CST) 5256 /* Propagate nonnull. */ 5257 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp); 5258 return NULL_TREE; 5259 5260 case NOP_EXPR: 5261 case CONVERT_EXPR: 5262 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp); 5263 5264 case ADDR_EXPR: 5265 instance = TREE_OPERAND (instance, 0); 5266 if (nonnull) 5267 { 5268 /* Just because we see an ADDR_EXPR doesn't mean we're dealing 5269 with a real object -- given &p->f, p can still be null. */ 5270 tree t = get_base_address (instance); 5271 /* ??? Probably should check DECL_WEAK here. */ 5272 if (t && DECL_P (t)) 5273 *nonnull = 1; 5274 } 5275 return fixed_type_or_null (instance, nonnull, cdtorp); 5276 5277 case COMPONENT_REF: 5278 /* If this component is really a base class reference, then the field 5279 itself isn't definitive. */ 5280 if (DECL_FIELD_IS_BASE (TREE_OPERAND (instance, 1))) 5281 return fixed_type_or_null (TREE_OPERAND (instance, 0), nonnull, cdtorp); 5282 return fixed_type_or_null (TREE_OPERAND (instance, 1), nonnull, cdtorp); 5283 5284 case VAR_DECL: 5285 case FIELD_DECL: 5286 if (TREE_CODE (TREE_TYPE (instance)) == ARRAY_TYPE 5287 && IS_AGGR_TYPE (TREE_TYPE (TREE_TYPE (instance)))) 5288 { 5289 if (nonnull) 5290 *nonnull = 1; 5291 return TREE_TYPE (TREE_TYPE (instance)); 5292 } 5293 /* fall through... */ 5294 case TARGET_EXPR: 5295 case PARM_DECL: 5296 case RESULT_DECL: 5297 if (IS_AGGR_TYPE (TREE_TYPE (instance))) 5298 { 5299 if (nonnull) 5300 *nonnull = 1; 5301 return TREE_TYPE (instance); 5302 } 5303 else if (instance == current_class_ptr) 5304 { 5305 if (nonnull) 5306 *nonnull = 1; 5307 5308 /* if we're in a ctor or dtor, we know our type. */ 5309 if (DECL_LANG_SPECIFIC (current_function_decl) 5310 && (DECL_CONSTRUCTOR_P (current_function_decl) 5311 || DECL_DESTRUCTOR_P (current_function_decl))) 5312 { 5313 if (cdtorp) 5314 *cdtorp = 1; 5315 return TREE_TYPE (TREE_TYPE (instance)); 5316 } 5317 } 5318 else if (TREE_CODE (TREE_TYPE (instance)) == REFERENCE_TYPE) 5319 { 5320 /* Reference variables should be references to objects. */ 5321 if (nonnull) 5322 *nonnull = 1; 5323 5324 /* DECL_VAR_MARKED_P is used to prevent recursion; a 5325 variable's initializer may refer to the variable 5326 itself. */ 5327 if (TREE_CODE (instance) == VAR_DECL 5328 && DECL_INITIAL (instance) 5329 && !DECL_VAR_MARKED_P (instance)) 5330 { 5331 tree type; 5332 DECL_VAR_MARKED_P (instance) = 1; 5333 type = fixed_type_or_null (DECL_INITIAL (instance), 5334 nonnull, cdtorp); 5335 DECL_VAR_MARKED_P (instance) = 0; 5336 return type; 5337 } 5338 } 5339 return NULL_TREE; 5340 5341 default: 5342 return NULL_TREE; 5343 } 5344} 5345 5346/* Return nonzero if the dynamic type of INSTANCE is known, and 5347 equivalent to the static type. We also handle the case where 5348 INSTANCE is really a pointer. Return negative if this is a 5349 ctor/dtor. There the dynamic type is known, but this might not be 5350 the most derived base of the original object, and hence virtual 5351 bases may not be layed out according to this type. 5352 5353 Used to determine whether the virtual function table is needed 5354 or not. 5355 5356 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless 5357 of our knowledge of its type. *NONNULL should be initialized 5358 before this function is called. */ 5359 5360int 5361resolves_to_fixed_type_p (tree instance, int* nonnull) 5362{ 5363 tree t = TREE_TYPE (instance); 5364 int cdtorp = 0; 5365 5366 tree fixed = fixed_type_or_null (instance, nonnull, &cdtorp); 5367 if (fixed == NULL_TREE) 5368 return 0; 5369 if (POINTER_TYPE_P (t)) 5370 t = TREE_TYPE (t); 5371 if (!same_type_ignoring_top_level_qualifiers_p (t, fixed)) 5372 return 0; 5373 return cdtorp ? -1 : 1; 5374} 5375 5376 5377void 5378init_class_processing (void) 5379{ 5380 current_class_depth = 0; 5381 current_class_stack_size = 10; 5382 current_class_stack 5383 = xmalloc (current_class_stack_size * sizeof (struct class_stack_node)); 5384 local_classes = VEC_alloc (tree, gc, 8); 5385 sizeof_biggest_empty_class = size_zero_node; 5386 5387 ridpointers[(int) RID_PUBLIC] = access_public_node; 5388 ridpointers[(int) RID_PRIVATE] = access_private_node; 5389 ridpointers[(int) RID_PROTECTED] = access_protected_node; 5390} 5391 5392/* Restore the cached PREVIOUS_CLASS_LEVEL. */ 5393 5394static void 5395restore_class_cache (void) 5396{ 5397 tree type; 5398 5399 /* We are re-entering the same class we just left, so we don't 5400 have to search the whole inheritance matrix to find all the 5401 decls to bind again. Instead, we install the cached 5402 class_shadowed list and walk through it binding names. */ 5403 push_binding_level (previous_class_level); 5404 class_binding_level = previous_class_level; 5405 /* Restore IDENTIFIER_TYPE_VALUE. */ 5406 for (type = class_binding_level->type_shadowed; 5407 type; 5408 type = TREE_CHAIN (type)) 5409 SET_IDENTIFIER_TYPE_VALUE (TREE_PURPOSE (type), TREE_TYPE (type)); 5410} 5411 5412/* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as 5413 appropriate for TYPE. 5414 5415 So that we may avoid calls to lookup_name, we cache the _TYPE 5416 nodes of local TYPE_DECLs in the TREE_TYPE field of the name. 5417 5418 For multiple inheritance, we perform a two-pass depth-first search 5419 of the type lattice. */ 5420 5421void 5422pushclass (tree type) 5423{ 5424 class_stack_node_t csn; 5425 5426 type = TYPE_MAIN_VARIANT (type); 5427 5428 /* Make sure there is enough room for the new entry on the stack. */ 5429 if (current_class_depth + 1 >= current_class_stack_size) 5430 { 5431 current_class_stack_size *= 2; 5432 current_class_stack 5433 = xrealloc (current_class_stack, 5434 current_class_stack_size 5435 * sizeof (struct class_stack_node)); 5436 } 5437 5438 /* Insert a new entry on the class stack. */ 5439 csn = current_class_stack + current_class_depth; 5440 csn->name = current_class_name; 5441 csn->type = current_class_type; 5442 csn->access = current_access_specifier; 5443 csn->names_used = 0; 5444 csn->hidden = 0; 5445 current_class_depth++; 5446 5447 /* Now set up the new type. */ 5448 current_class_name = TYPE_NAME (type); 5449 if (TREE_CODE (current_class_name) == TYPE_DECL) 5450 current_class_name = DECL_NAME (current_class_name); 5451 current_class_type = type; 5452 5453 /* By default, things in classes are private, while things in 5454 structures or unions are public. */ 5455 current_access_specifier = (CLASSTYPE_DECLARED_CLASS (type) 5456 ? access_private_node 5457 : access_public_node); 5458 5459 if (previous_class_level 5460 && type != previous_class_level->this_entity 5461 && current_class_depth == 1) 5462 { 5463 /* Forcibly remove any old class remnants. */ 5464 invalidate_class_lookup_cache (); 5465 } 5466 5467 if (!previous_class_level 5468 || type != previous_class_level->this_entity 5469 || current_class_depth > 1) 5470 pushlevel_class (); 5471 else 5472 restore_class_cache (); 5473} 5474 5475/* When we exit a toplevel class scope, we save its binding level so 5476 that we can restore it quickly. Here, we've entered some other 5477 class, so we must invalidate our cache. */ 5478 5479void 5480invalidate_class_lookup_cache (void) 5481{ 5482 previous_class_level = NULL; 5483} 5484 5485/* Get out of the current class scope. If we were in a class scope 5486 previously, that is the one popped to. */ 5487 5488void 5489popclass (void) 5490{ 5491 poplevel_class (); 5492 5493 current_class_depth--; 5494 current_class_name = current_class_stack[current_class_depth].name; 5495 current_class_type = current_class_stack[current_class_depth].type; 5496 current_access_specifier = current_class_stack[current_class_depth].access; 5497 if (current_class_stack[current_class_depth].names_used) 5498 splay_tree_delete (current_class_stack[current_class_depth].names_used); 5499} 5500 5501/* Mark the top of the class stack as hidden. */ 5502 5503void 5504push_class_stack (void) 5505{ 5506 if (current_class_depth) 5507 ++current_class_stack[current_class_depth - 1].hidden; 5508} 5509 5510/* Mark the top of the class stack as un-hidden. */ 5511 5512void 5513pop_class_stack (void) 5514{ 5515 if (current_class_depth) 5516 --current_class_stack[current_class_depth - 1].hidden; 5517} 5518 5519/* Returns 1 if current_class_type is either T or a nested type of T. 5520 We start looking from 1 because entry 0 is from global scope, and has 5521 no type. */ 5522 5523int 5524currently_open_class (tree t) 5525{ 5526 int i; 5527 if (current_class_type && same_type_p (t, current_class_type)) 5528 return 1; 5529 for (i = current_class_depth - 1; i > 0; --i) 5530 { 5531 if (current_class_stack[i].hidden) 5532 break; 5533 if (current_class_stack[i].type 5534 && same_type_p (current_class_stack [i].type, t)) 5535 return 1; 5536 } 5537 return 0; 5538} 5539 5540/* If either current_class_type or one of its enclosing classes are derived 5541 from T, return the appropriate type. Used to determine how we found 5542 something via unqualified lookup. */ 5543 5544tree 5545currently_open_derived_class (tree t) 5546{ 5547 int i; 5548 5549 /* The bases of a dependent type are unknown. */ 5550 if (dependent_type_p (t)) 5551 return NULL_TREE; 5552 5553 if (!current_class_type) 5554 return NULL_TREE; 5555 5556 if (DERIVED_FROM_P (t, current_class_type)) 5557 return current_class_type; 5558 5559 for (i = current_class_depth - 1; i > 0; --i) 5560 { 5561 if (current_class_stack[i].hidden) 5562 break; 5563 if (DERIVED_FROM_P (t, current_class_stack[i].type)) 5564 return current_class_stack[i].type; 5565 } 5566 5567 return NULL_TREE; 5568} 5569 5570/* When entering a class scope, all enclosing class scopes' names with 5571 static meaning (static variables, static functions, types and 5572 enumerators) have to be visible. This recursive function calls 5573 pushclass for all enclosing class contexts until global or a local 5574 scope is reached. TYPE is the enclosed class. */ 5575 5576void 5577push_nested_class (tree type) 5578{ 5579 tree context; 5580 5581 /* A namespace might be passed in error cases, like A::B:C. */ 5582 if (type == NULL_TREE 5583 || type == error_mark_node 5584 || TREE_CODE (type) == NAMESPACE_DECL 5585 || ! IS_AGGR_TYPE (type) 5586 || TREE_CODE (type) == TEMPLATE_TYPE_PARM 5587 || TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM) 5588 return; 5589 5590 context = DECL_CONTEXT (TYPE_MAIN_DECL (type)); 5591 5592 if (context && CLASS_TYPE_P (context)) 5593 push_nested_class (context); 5594 pushclass (type); 5595} 5596 5597/* Undoes a push_nested_class call. */ 5598 5599void 5600pop_nested_class (void) 5601{ 5602 tree context = DECL_CONTEXT (TYPE_MAIN_DECL (current_class_type)); 5603 5604 popclass (); 5605 if (context && CLASS_TYPE_P (context)) 5606 pop_nested_class (); 5607} 5608 5609/* Returns the number of extern "LANG" blocks we are nested within. */ 5610 5611int 5612current_lang_depth (void) 5613{ 5614 return VEC_length (tree, current_lang_base); 5615} 5616 5617/* Set global variables CURRENT_LANG_NAME to appropriate value 5618 so that behavior of name-mangling machinery is correct. */ 5619 5620void 5621push_lang_context (tree name) 5622{ 5623 VEC_safe_push (tree, gc, current_lang_base, current_lang_name); 5624 5625 if (name == lang_name_cplusplus) 5626 { 5627 current_lang_name = name; 5628 } 5629 else if (name == lang_name_java) 5630 { 5631 current_lang_name = name; 5632 /* DECL_IGNORED_P is initially set for these types, to avoid clutter. 5633 (See record_builtin_java_type in decl.c.) However, that causes 5634 incorrect debug entries if these types are actually used. 5635 So we re-enable debug output after extern "Java". */ 5636 DECL_IGNORED_P (TYPE_NAME (java_byte_type_node)) = 0; 5637 DECL_IGNORED_P (TYPE_NAME (java_short_type_node)) = 0; 5638 DECL_IGNORED_P (TYPE_NAME (java_int_type_node)) = 0; 5639 DECL_IGNORED_P (TYPE_NAME (java_long_type_node)) = 0; 5640 DECL_IGNORED_P (TYPE_NAME (java_float_type_node)) = 0; 5641 DECL_IGNORED_P (TYPE_NAME (java_double_type_node)) = 0; 5642 DECL_IGNORED_P (TYPE_NAME (java_char_type_node)) = 0; 5643 DECL_IGNORED_P (TYPE_NAME (java_boolean_type_node)) = 0; 5644 } 5645 else if (name == lang_name_c) 5646 { 5647 current_lang_name = name; 5648 } 5649 else 5650 error ("language string %<\"%E\"%> not recognized", name); 5651} 5652 5653/* Get out of the current language scope. */ 5654 5655void 5656pop_lang_context (void) 5657{ 5658 current_lang_name = VEC_pop (tree, current_lang_base); 5659} 5660 5661/* Type instantiation routines. */ 5662 5663/* Given an OVERLOAD and a TARGET_TYPE, return the function that 5664 matches the TARGET_TYPE. If there is no satisfactory match, return 5665 error_mark_node, and issue an error & warning messages under control 5666 of FLAGS. Permit pointers to member function if FLAGS permits. If 5667 TEMPLATE_ONLY, the name of the overloaded function was a 5668 template-id, and EXPLICIT_TARGS are the explicitly provided 5669 template arguments. */ 5670 5671static tree 5672resolve_address_of_overloaded_function (tree target_type, 5673 tree overload, 5674 tsubst_flags_t flags, 5675 bool template_only, 5676 tree explicit_targs) 5677{ 5678 /* Here's what the standard says: 5679 5680 [over.over] 5681 5682 If the name is a function template, template argument deduction 5683 is done, and if the argument deduction succeeds, the deduced 5684 arguments are used to generate a single template function, which 5685 is added to the set of overloaded functions considered. 5686 5687 Non-member functions and static member functions match targets of 5688 type "pointer-to-function" or "reference-to-function." Nonstatic 5689 member functions match targets of type "pointer-to-member 5690 function;" the function type of the pointer to member is used to 5691 select the member function from the set of overloaded member 5692 functions. If a nonstatic member function is selected, the 5693 reference to the overloaded function name is required to have the 5694 form of a pointer to member as described in 5.3.1. 5695 5696 If more than one function is selected, any template functions in 5697 the set are eliminated if the set also contains a non-template 5698 function, and any given template function is eliminated if the 5699 set contains a second template function that is more specialized 5700 than the first according to the partial ordering rules 14.5.5.2. 5701 After such eliminations, if any, there shall remain exactly one 5702 selected function. */ 5703 5704 int is_ptrmem = 0; 5705 int is_reference = 0; 5706 /* We store the matches in a TREE_LIST rooted here. The functions 5707 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy 5708 interoperability with most_specialized_instantiation. */ 5709 tree matches = NULL_TREE; 5710 tree fn; 5711 5712 /* By the time we get here, we should be seeing only real 5713 pointer-to-member types, not the internal POINTER_TYPE to 5714 METHOD_TYPE representation. */ 5715 gcc_assert (TREE_CODE (target_type) != POINTER_TYPE 5716 || TREE_CODE (TREE_TYPE (target_type)) != METHOD_TYPE); 5717 5718 gcc_assert (is_overloaded_fn (overload)); 5719 5720 /* Check that the TARGET_TYPE is reasonable. */ 5721 if (TYPE_PTRFN_P (target_type)) 5722 /* This is OK. */; 5723 else if (TYPE_PTRMEMFUNC_P (target_type)) 5724 /* This is OK, too. */ 5725 is_ptrmem = 1; 5726 else if (TREE_CODE (target_type) == FUNCTION_TYPE) 5727 { 5728 /* This is OK, too. This comes from a conversion to reference 5729 type. */ 5730 target_type = build_reference_type (target_type); 5731 is_reference = 1; 5732 } 5733 else 5734 { 5735 if (flags & tf_error) 5736 error ("cannot resolve overloaded function %qD based on" 5737 " conversion to type %qT", 5738 DECL_NAME (OVL_FUNCTION (overload)), target_type); 5739 return error_mark_node; 5740 } 5741 5742 /* If we can find a non-template function that matches, we can just 5743 use it. There's no point in generating template instantiations 5744 if we're just going to throw them out anyhow. But, of course, we 5745 can only do this when we don't *need* a template function. */ 5746 if (!template_only) 5747 { 5748 tree fns; 5749 5750 for (fns = overload; fns; fns = OVL_NEXT (fns)) 5751 { 5752 tree fn = OVL_CURRENT (fns); 5753 tree fntype; 5754 5755 if (TREE_CODE (fn) == TEMPLATE_DECL) 5756 /* We're not looking for templates just yet. */ 5757 continue; 5758 5759 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE) 5760 != is_ptrmem) 5761 /* We're looking for a non-static member, and this isn't 5762 one, or vice versa. */ 5763 continue; 5764 5765 /* Ignore functions which haven't been explicitly 5766 declared. */ 5767 if (DECL_ANTICIPATED (fn)) 5768 continue; 5769 5770 /* See if there's a match. */ 5771 fntype = TREE_TYPE (fn); 5772 if (is_ptrmem) 5773 fntype = build_ptrmemfunc_type (build_pointer_type (fntype)); 5774 else if (!is_reference) 5775 fntype = build_pointer_type (fntype); 5776 5777 if (can_convert_arg (target_type, fntype, fn, LOOKUP_NORMAL)) 5778 matches = tree_cons (fn, NULL_TREE, matches); 5779 } 5780 } 5781 5782 /* Now, if we've already got a match (or matches), there's no need 5783 to proceed to the template functions. But, if we don't have a 5784 match we need to look at them, too. */ 5785 if (!matches) 5786 { 5787 tree target_fn_type; 5788 tree target_arg_types; 5789 tree target_ret_type; 5790 tree fns; 5791 5792 if (is_ptrmem) 5793 target_fn_type 5794 = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (target_type)); 5795 else 5796 target_fn_type = TREE_TYPE (target_type); 5797 target_arg_types = TYPE_ARG_TYPES (target_fn_type); 5798 target_ret_type = TREE_TYPE (target_fn_type); 5799 5800 /* Never do unification on the 'this' parameter. */ 5801 if (TREE_CODE (target_fn_type) == METHOD_TYPE) 5802 target_arg_types = TREE_CHAIN (target_arg_types); 5803 5804 for (fns = overload; fns; fns = OVL_NEXT (fns)) 5805 { 5806 tree fn = OVL_CURRENT (fns); 5807 tree instantiation; 5808 tree instantiation_type; 5809 tree targs; 5810 5811 if (TREE_CODE (fn) != TEMPLATE_DECL) 5812 /* We're only looking for templates. */ 5813 continue; 5814 5815 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE) 5816 != is_ptrmem) 5817 /* We're not looking for a non-static member, and this is 5818 one, or vice versa. */ 5819 continue; 5820 5821 /* Try to do argument deduction. */ 5822 targs = make_tree_vec (DECL_NTPARMS (fn)); 5823 if (fn_type_unification (fn, explicit_targs, targs, 5824 target_arg_types, target_ret_type, 5825 DEDUCE_EXACT, LOOKUP_NORMAL)) 5826 /* Argument deduction failed. */ 5827 continue; 5828 5829 /* Instantiate the template. */ 5830 instantiation = instantiate_template (fn, targs, flags); 5831 if (instantiation == error_mark_node) 5832 /* Instantiation failed. */ 5833 continue; 5834 5835 /* See if there's a match. */ 5836 instantiation_type = TREE_TYPE (instantiation); 5837 if (is_ptrmem) 5838 instantiation_type = 5839 build_ptrmemfunc_type (build_pointer_type (instantiation_type)); 5840 else if (!is_reference) 5841 instantiation_type = build_pointer_type (instantiation_type); 5842 if (can_convert_arg (target_type, instantiation_type, instantiation, 5843 LOOKUP_NORMAL)) 5844 matches = tree_cons (instantiation, fn, matches); 5845 } 5846 5847 /* Now, remove all but the most specialized of the matches. */ 5848 if (matches) 5849 { 5850 tree match = most_specialized_instantiation (matches); 5851 5852 if (match != error_mark_node) 5853 matches = tree_cons (match, NULL_TREE, NULL_TREE); 5854 } 5855 } 5856 5857 /* Now we should have exactly one function in MATCHES. */ 5858 if (matches == NULL_TREE) 5859 { 5860 /* There were *no* matches. */ 5861 if (flags & tf_error) 5862 { 5863 error ("no matches converting function %qD to type %q#T", 5864 DECL_NAME (OVL_FUNCTION (overload)), 5865 target_type); 5866 5867 /* print_candidates expects a chain with the functions in 5868 TREE_VALUE slots, so we cons one up here (we're losing anyway, 5869 so why be clever?). */ 5870 for (; overload; overload = OVL_NEXT (overload)) 5871 matches = tree_cons (NULL_TREE, OVL_CURRENT (overload), 5872 matches); 5873 5874 print_candidates (matches); 5875 } 5876 return error_mark_node; 5877 } 5878 else if (TREE_CHAIN (matches)) 5879 { 5880 /* There were too many matches. */ 5881 5882 if (flags & tf_error) 5883 { 5884 tree match; 5885 5886 error ("converting overloaded function %qD to type %q#T is ambiguous", 5887 DECL_NAME (OVL_FUNCTION (overload)), 5888 target_type); 5889 5890 /* Since print_candidates expects the functions in the 5891 TREE_VALUE slot, we flip them here. */ 5892 for (match = matches; match; match = TREE_CHAIN (match)) 5893 TREE_VALUE (match) = TREE_PURPOSE (match); 5894 5895 print_candidates (matches); 5896 } 5897 5898 return error_mark_node; 5899 } 5900 5901 /* Good, exactly one match. Now, convert it to the correct type. */ 5902 fn = TREE_PURPOSE (matches); 5903 5904 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn) 5905 && !(flags & tf_ptrmem_ok) && !flag_ms_extensions) 5906 { 5907 static int explained; 5908 5909 if (!(flags & tf_error)) 5910 return error_mark_node; 5911 5912 pedwarn ("assuming pointer to member %qD", fn); 5913 if (!explained) 5914 { 5915 pedwarn ("(a pointer to member can only be formed with %<&%E%>)", fn); 5916 explained = 1; 5917 } 5918 } 5919 5920 /* If we're doing overload resolution purely for the purpose of 5921 determining conversion sequences, we should not consider the 5922 function used. If this conversion sequence is selected, the 5923 function will be marked as used at this point. */ 5924 if (!(flags & tf_conv)) 5925 mark_used (fn); 5926 5927 if (TYPE_PTRFN_P (target_type) || TYPE_PTRMEMFUNC_P (target_type)) 5928 return build_unary_op (ADDR_EXPR, fn, 0); 5929 else 5930 { 5931 /* The target must be a REFERENCE_TYPE. Above, build_unary_op 5932 will mark the function as addressed, but here we must do it 5933 explicitly. */ 5934 cxx_mark_addressable (fn); 5935 5936 return fn; 5937 } 5938} 5939 5940/* This function will instantiate the type of the expression given in 5941 RHS to match the type of LHSTYPE. If errors exist, then return 5942 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then 5943 we complain on errors. If we are not complaining, never modify rhs, 5944 as overload resolution wants to try many possible instantiations, in 5945 the hope that at least one will work. 5946 5947 For non-recursive calls, LHSTYPE should be a function, pointer to 5948 function, or a pointer to member function. */ 5949 5950tree 5951instantiate_type (tree lhstype, tree rhs, tsubst_flags_t flags) 5952{ 5953 tsubst_flags_t flags_in = flags; 5954 5955 flags &= ~tf_ptrmem_ok; 5956 5957 if (TREE_CODE (lhstype) == UNKNOWN_TYPE) 5958 { 5959 if (flags & tf_error) 5960 error ("not enough type information"); 5961 return error_mark_node; 5962 } 5963 5964 if (TREE_TYPE (rhs) != NULL_TREE && ! (type_unknown_p (rhs))) 5965 { 5966 if (same_type_p (lhstype, TREE_TYPE (rhs))) 5967 return rhs; 5968 if (flag_ms_extensions 5969 && TYPE_PTRMEMFUNC_P (lhstype) 5970 && !TYPE_PTRMEMFUNC_P (TREE_TYPE (rhs))) 5971 /* Microsoft allows `A::f' to be resolved to a 5972 pointer-to-member. */ 5973 ; 5974 else 5975 { 5976 if (flags & tf_error) 5977 error ("argument of type %qT does not match %qT", 5978 TREE_TYPE (rhs), lhstype); 5979 return error_mark_node; 5980 } 5981 } 5982 5983 if (TREE_CODE (rhs) == BASELINK) 5984 rhs = BASELINK_FUNCTIONS (rhs); 5985 5986 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot 5987 deduce any type information. */ 5988 if (TREE_CODE (rhs) == NON_DEPENDENT_EXPR) 5989 { 5990 if (flags & tf_error) 5991 error ("not enough type information"); 5992 return error_mark_node; 5993 } 5994 5995 /* We don't overwrite rhs if it is an overloaded function. 5996 Copying it would destroy the tree link. */ 5997 if (TREE_CODE (rhs) != OVERLOAD) 5998 rhs = copy_node (rhs); 5999 6000 /* This should really only be used when attempting to distinguish 6001 what sort of a pointer to function we have. For now, any 6002 arithmetic operation which is not supported on pointers 6003 is rejected as an error. */ 6004 6005 switch (TREE_CODE (rhs)) 6006 { 6007 case TYPE_EXPR: 6008 case CONVERT_EXPR: 6009 case SAVE_EXPR: 6010 case CONSTRUCTOR: 6011 gcc_unreachable (); 6012 6013 case INDIRECT_REF: 6014 case ARRAY_REF: 6015 { 6016 tree new_rhs; 6017 6018 new_rhs = instantiate_type (build_pointer_type (lhstype), 6019 TREE_OPERAND (rhs, 0), flags); 6020 if (new_rhs == error_mark_node) 6021 return error_mark_node; 6022 6023 TREE_TYPE (rhs) = lhstype; 6024 TREE_OPERAND (rhs, 0) = new_rhs; 6025 return rhs; 6026 } 6027 6028 case NOP_EXPR: 6029 rhs = copy_node (TREE_OPERAND (rhs, 0)); 6030 TREE_TYPE (rhs) = unknown_type_node; 6031 return instantiate_type (lhstype, rhs, flags); 6032 6033 case COMPONENT_REF: 6034 { 6035 tree member = TREE_OPERAND (rhs, 1); 6036 6037 member = instantiate_type (lhstype, member, flags); 6038 if (member != error_mark_node 6039 && TREE_SIDE_EFFECTS (TREE_OPERAND (rhs, 0))) 6040 /* Do not lose object's side effects. */ 6041 return build2 (COMPOUND_EXPR, TREE_TYPE (member), 6042 TREE_OPERAND (rhs, 0), member); 6043 return member; 6044 } 6045 6046 case OFFSET_REF: 6047 rhs = TREE_OPERAND (rhs, 1); 6048 if (BASELINK_P (rhs)) 6049 return instantiate_type (lhstype, BASELINK_FUNCTIONS (rhs), flags_in); 6050 6051 /* This can happen if we are forming a pointer-to-member for a 6052 member template. */ 6053 gcc_assert (TREE_CODE (rhs) == TEMPLATE_ID_EXPR); 6054 6055 /* Fall through. */ 6056 6057 case TEMPLATE_ID_EXPR: 6058 { 6059 tree fns = TREE_OPERAND (rhs, 0); 6060 tree args = TREE_OPERAND (rhs, 1); 6061 6062 return 6063 resolve_address_of_overloaded_function (lhstype, fns, flags_in, 6064 /*template_only=*/true, 6065 args); 6066 } 6067 6068 case OVERLOAD: 6069 case FUNCTION_DECL: 6070 return 6071 resolve_address_of_overloaded_function (lhstype, rhs, flags_in, 6072 /*template_only=*/false, 6073 /*explicit_targs=*/NULL_TREE); 6074 6075 case CALL_EXPR: 6076 /* This is too hard for now. */ 6077 gcc_unreachable (); 6078 6079 case PLUS_EXPR: 6080 case MINUS_EXPR: 6081 case COMPOUND_EXPR: 6082 TREE_OPERAND (rhs, 0) 6083 = instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags); 6084 if (TREE_OPERAND (rhs, 0) == error_mark_node) 6085 return error_mark_node; 6086 TREE_OPERAND (rhs, 1) 6087 = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags); 6088 if (TREE_OPERAND (rhs, 1) == error_mark_node) 6089 return error_mark_node; 6090 6091 TREE_TYPE (rhs) = lhstype; 6092 return rhs; 6093 6094 case MULT_EXPR: 6095 case TRUNC_DIV_EXPR: 6096 case FLOOR_DIV_EXPR: 6097 case CEIL_DIV_EXPR: 6098 case ROUND_DIV_EXPR: 6099 case RDIV_EXPR: 6100 case TRUNC_MOD_EXPR: 6101 case FLOOR_MOD_EXPR: 6102 case CEIL_MOD_EXPR: 6103 case ROUND_MOD_EXPR: 6104 case FIX_ROUND_EXPR: 6105 case FIX_FLOOR_EXPR: 6106 case FIX_CEIL_EXPR: 6107 case FIX_TRUNC_EXPR: 6108 case FLOAT_EXPR: 6109 case NEGATE_EXPR: 6110 case ABS_EXPR: 6111 case MAX_EXPR: 6112 case MIN_EXPR: 6113 6114 case BIT_AND_EXPR: 6115 case BIT_IOR_EXPR: 6116 case BIT_XOR_EXPR: 6117 case LSHIFT_EXPR: 6118 case RSHIFT_EXPR: 6119 case LROTATE_EXPR: 6120 case RROTATE_EXPR: 6121 6122 case PREINCREMENT_EXPR: 6123 case PREDECREMENT_EXPR: 6124 case POSTINCREMENT_EXPR: 6125 case POSTDECREMENT_EXPR: 6126 if (flags & tf_error) 6127 error ("invalid operation on uninstantiated type"); 6128 return error_mark_node; 6129 6130 case TRUTH_AND_EXPR: 6131 case TRUTH_OR_EXPR: 6132 case TRUTH_XOR_EXPR: 6133 case LT_EXPR: 6134 case LE_EXPR: 6135 case GT_EXPR: 6136 case GE_EXPR: 6137 case EQ_EXPR: 6138 case NE_EXPR: 6139 case TRUTH_ANDIF_EXPR: 6140 case TRUTH_ORIF_EXPR: 6141 case TRUTH_NOT_EXPR: 6142 if (flags & tf_error) 6143 error ("not enough type information"); 6144 return error_mark_node; 6145 6146 case COND_EXPR: 6147 if (type_unknown_p (TREE_OPERAND (rhs, 0))) 6148 { 6149 if (flags & tf_error) 6150 error ("not enough type information"); 6151 return error_mark_node; 6152 } 6153 TREE_OPERAND (rhs, 1) 6154 = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags); 6155 if (TREE_OPERAND (rhs, 1) == error_mark_node) 6156 return error_mark_node; 6157 TREE_OPERAND (rhs, 2) 6158 = instantiate_type (lhstype, TREE_OPERAND (rhs, 2), flags); 6159 if (TREE_OPERAND (rhs, 2) == error_mark_node) 6160 return error_mark_node; 6161 6162 TREE_TYPE (rhs) = lhstype; 6163 return rhs; 6164 6165 case MODIFY_EXPR: 6166 TREE_OPERAND (rhs, 1) 6167 = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags); 6168 if (TREE_OPERAND (rhs, 1) == error_mark_node) 6169 return error_mark_node; 6170 6171 TREE_TYPE (rhs) = lhstype; 6172 return rhs; 6173 6174 case ADDR_EXPR: 6175 { 6176 if (PTRMEM_OK_P (rhs)) 6177 flags |= tf_ptrmem_ok; 6178 6179 return instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags); 6180 } 6181 6182 case ERROR_MARK: 6183 return error_mark_node; 6184 6185 default: 6186 gcc_unreachable (); 6187 } 6188 return error_mark_node; 6189} 6190 6191/* Return the name of the virtual function pointer field 6192 (as an IDENTIFIER_NODE) for the given TYPE. Note that 6193 this may have to look back through base types to find the 6194 ultimate field name. (For single inheritance, these could 6195 all be the same name. Who knows for multiple inheritance). */ 6196 6197static tree 6198get_vfield_name (tree type) 6199{ 6200 tree binfo, base_binfo; 6201 char *buf; 6202 6203 for (binfo = TYPE_BINFO (type); 6204 BINFO_N_BASE_BINFOS (binfo); 6205 binfo = base_binfo) 6206 { 6207 base_binfo = BINFO_BASE_BINFO (binfo, 0); 6208 6209 if (BINFO_VIRTUAL_P (base_binfo) 6210 || !TYPE_CONTAINS_VPTR_P (BINFO_TYPE (base_binfo))) 6211 break; 6212 } 6213 6214 type = BINFO_TYPE (binfo); 6215 buf = alloca (sizeof (VFIELD_NAME_FORMAT) + TYPE_NAME_LENGTH (type) + 2); 6216 sprintf (buf, VFIELD_NAME_FORMAT, 6217 IDENTIFIER_POINTER (constructor_name (type))); 6218 return get_identifier (buf); 6219} 6220 6221void 6222print_class_statistics (void) 6223{ 6224#ifdef GATHER_STATISTICS 6225 fprintf (stderr, "convert_harshness = %d\n", n_convert_harshness); 6226 fprintf (stderr, "compute_conversion_costs = %d\n", n_compute_conversion_costs); 6227 if (n_vtables) 6228 { 6229 fprintf (stderr, "vtables = %d; vtable searches = %d\n", 6230 n_vtables, n_vtable_searches); 6231 fprintf (stderr, "vtable entries = %d; vtable elems = %d\n", 6232 n_vtable_entries, n_vtable_elems); 6233 } 6234#endif 6235} 6236 6237/* Build a dummy reference to ourselves so Derived::Base (and A::A) works, 6238 according to [class]: 6239 The class-name is also inserted 6240 into the scope of the class itself. For purposes of access checking, 6241 the inserted class name is treated as if it were a public member name. */ 6242 6243void 6244build_self_reference (void) 6245{ 6246 tree name = constructor_name (current_class_type); 6247 tree value = build_lang_decl (TYPE_DECL, name, current_class_type); 6248 tree saved_cas; 6249 6250 DECL_NONLOCAL (value) = 1; 6251 DECL_CONTEXT (value) = current_class_type; 6252 DECL_ARTIFICIAL (value) = 1; 6253 SET_DECL_SELF_REFERENCE_P (value); 6254 6255 if (processing_template_decl) 6256 value = push_template_decl (value); 6257 6258 saved_cas = current_access_specifier; 6259 current_access_specifier = access_public_node; 6260 finish_member_declaration (value); 6261 current_access_specifier = saved_cas; 6262} 6263 6264/* Returns 1 if TYPE contains only padding bytes. */ 6265 6266int 6267is_empty_class (tree type) 6268{ 6269 if (type == error_mark_node) 6270 return 0; 6271 6272 if (! IS_AGGR_TYPE (type)) 6273 return 0; 6274 6275 /* In G++ 3.2, whether or not a class was empty was determined by 6276 looking at its size. */ 6277 if (abi_version_at_least (2)) 6278 return CLASSTYPE_EMPTY_P (type); 6279 else 6280 return integer_zerop (CLASSTYPE_SIZE (type)); 6281} 6282 6283/* Returns true if TYPE contains an empty class. */ 6284 6285static bool 6286contains_empty_class_p (tree type) 6287{ 6288 if (is_empty_class (type)) 6289 return true; 6290 if (CLASS_TYPE_P (type)) 6291 { 6292 tree field; 6293 tree binfo; 6294 tree base_binfo; 6295 int i; 6296 6297 for (binfo = TYPE_BINFO (type), i = 0; 6298 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 6299 if (contains_empty_class_p (BINFO_TYPE (base_binfo))) 6300 return true; 6301 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) 6302 if (TREE_CODE (field) == FIELD_DECL 6303 && !DECL_ARTIFICIAL (field) 6304 && is_empty_class (TREE_TYPE (field))) 6305 return true; 6306 } 6307 else if (TREE_CODE (type) == ARRAY_TYPE) 6308 return contains_empty_class_p (TREE_TYPE (type)); 6309 return false; 6310} 6311 6312/* Note that NAME was looked up while the current class was being 6313 defined and that the result of that lookup was DECL. */ 6314 6315void 6316maybe_note_name_used_in_class (tree name, tree decl) 6317{ 6318 splay_tree names_used; 6319 6320 /* If we're not defining a class, there's nothing to do. */ 6321 if (!(innermost_scope_kind() == sk_class 6322 && TYPE_BEING_DEFINED (current_class_type))) 6323 return; 6324 6325 /* If there's already a binding for this NAME, then we don't have 6326 anything to worry about. */ 6327 if (lookup_member (current_class_type, name, 6328 /*protect=*/0, /*want_type=*/false)) 6329 return; 6330 6331 if (!current_class_stack[current_class_depth - 1].names_used) 6332 current_class_stack[current_class_depth - 1].names_used 6333 = splay_tree_new (splay_tree_compare_pointers, 0, 0); 6334 names_used = current_class_stack[current_class_depth - 1].names_used; 6335 6336 splay_tree_insert (names_used, 6337 (splay_tree_key) name, 6338 (splay_tree_value) decl); 6339} 6340 6341/* Note that NAME was declared (as DECL) in the current class. Check 6342 to see that the declaration is valid. */ 6343 6344void 6345note_name_declared_in_class (tree name, tree decl) 6346{ 6347 splay_tree names_used; 6348 splay_tree_node n; 6349 6350 /* Look to see if we ever used this name. */ 6351 names_used 6352 = current_class_stack[current_class_depth - 1].names_used; 6353 if (!names_used) 6354 return; 6355 6356 n = splay_tree_lookup (names_used, (splay_tree_key) name); 6357 if (n) 6358 { 6359 /* [basic.scope.class] 6360 6361 A name N used in a class S shall refer to the same declaration 6362 in its context and when re-evaluated in the completed scope of 6363 S. */ 6364 error ("declaration of %q#D", decl); 6365 error ("changes meaning of %qD from %q+#D", 6366 DECL_NAME (OVL_CURRENT (decl)), (tree) n->value); 6367 } 6368} 6369 6370/* Returns the VAR_DECL for the complete vtable associated with BINFO. 6371 Secondary vtables are merged with primary vtables; this function 6372 will return the VAR_DECL for the primary vtable. */ 6373 6374tree 6375get_vtbl_decl_for_binfo (tree binfo) 6376{ 6377 tree decl; 6378 6379 decl = BINFO_VTABLE (binfo); 6380 if (decl && TREE_CODE (decl) == PLUS_EXPR) 6381 { 6382 gcc_assert (TREE_CODE (TREE_OPERAND (decl, 0)) == ADDR_EXPR); 6383 decl = TREE_OPERAND (TREE_OPERAND (decl, 0), 0); 6384 } 6385 if (decl) 6386 gcc_assert (TREE_CODE (decl) == VAR_DECL); 6387 return decl; 6388} 6389 6390 6391/* Returns the binfo for the primary base of BINFO. If the resulting 6392 BINFO is a virtual base, and it is inherited elsewhere in the 6393 hierarchy, then the returned binfo might not be the primary base of 6394 BINFO in the complete object. Check BINFO_PRIMARY_P or 6395 BINFO_LOST_PRIMARY_P to be sure. */ 6396 6397tree 6398get_primary_binfo (tree binfo) 6399{ 6400 tree primary_base; 6401 tree result; 6402 6403 primary_base = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (binfo)); 6404 if (!primary_base) 6405 return NULL_TREE; 6406 6407 result = copied_binfo (primary_base, binfo); 6408 return result; 6409} 6410 6411/* If INDENTED_P is zero, indent to INDENT. Return nonzero. */ 6412 6413static int 6414maybe_indent_hierarchy (FILE * stream, int indent, int indented_p) 6415{ 6416 if (!indented_p) 6417 fprintf (stream, "%*s", indent, ""); 6418 return 1; 6419} 6420 6421/* Dump the offsets of all the bases rooted at BINFO to STREAM. 6422 INDENT should be zero when called from the top level; it is 6423 incremented recursively. IGO indicates the next expected BINFO in 6424 inheritance graph ordering. */ 6425 6426static tree 6427dump_class_hierarchy_r (FILE *stream, 6428 int flags, 6429 tree binfo, 6430 tree igo, 6431 int indent) 6432{ 6433 int indented = 0; 6434 tree base_binfo; 6435 int i; 6436 6437 indented = maybe_indent_hierarchy (stream, indent, 0); 6438 fprintf (stream, "%s (0x%lx) ", 6439 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER), 6440 (unsigned long) binfo); 6441 if (binfo != igo) 6442 { 6443 fprintf (stream, "alternative-path\n"); 6444 return igo; 6445 } 6446 igo = TREE_CHAIN (binfo); 6447 6448 fprintf (stream, HOST_WIDE_INT_PRINT_DEC, 6449 tree_low_cst (BINFO_OFFSET (binfo), 0)); 6450 if (is_empty_class (BINFO_TYPE (binfo))) 6451 fprintf (stream, " empty"); 6452 else if (CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (binfo))) 6453 fprintf (stream, " nearly-empty"); 6454 if (BINFO_VIRTUAL_P (binfo)) 6455 fprintf (stream, " virtual"); 6456 fprintf (stream, "\n"); 6457 6458 indented = 0; 6459 if (BINFO_PRIMARY_P (binfo)) 6460 { 6461 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 6462 fprintf (stream, " primary-for %s (0x%lx)", 6463 type_as_string (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)), 6464 TFF_PLAIN_IDENTIFIER), 6465 (unsigned long)BINFO_INHERITANCE_CHAIN (binfo)); 6466 } 6467 if (BINFO_LOST_PRIMARY_P (binfo)) 6468 { 6469 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 6470 fprintf (stream, " lost-primary"); 6471 } 6472 if (indented) 6473 fprintf (stream, "\n"); 6474 6475 if (!(flags & TDF_SLIM)) 6476 { 6477 int indented = 0; 6478 6479 if (BINFO_SUBVTT_INDEX (binfo)) 6480 { 6481 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 6482 fprintf (stream, " subvttidx=%s", 6483 expr_as_string (BINFO_SUBVTT_INDEX (binfo), 6484 TFF_PLAIN_IDENTIFIER)); 6485 } 6486 if (BINFO_VPTR_INDEX (binfo)) 6487 { 6488 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 6489 fprintf (stream, " vptridx=%s", 6490 expr_as_string (BINFO_VPTR_INDEX (binfo), 6491 TFF_PLAIN_IDENTIFIER)); 6492 } 6493 if (BINFO_VPTR_FIELD (binfo)) 6494 { 6495 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 6496 fprintf (stream, " vbaseoffset=%s", 6497 expr_as_string (BINFO_VPTR_FIELD (binfo), 6498 TFF_PLAIN_IDENTIFIER)); 6499 } 6500 if (BINFO_VTABLE (binfo)) 6501 { 6502 indented = maybe_indent_hierarchy (stream, indent + 3, indented); 6503 fprintf (stream, " vptr=%s", 6504 expr_as_string (BINFO_VTABLE (binfo), 6505 TFF_PLAIN_IDENTIFIER)); 6506 } 6507 6508 if (indented) 6509 fprintf (stream, "\n"); 6510 } 6511 6512 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++) 6513 igo = dump_class_hierarchy_r (stream, flags, base_binfo, igo, indent + 2); 6514 6515 return igo; 6516} 6517 6518/* Dump the BINFO hierarchy for T. */ 6519 6520static void 6521dump_class_hierarchy_1 (FILE *stream, int flags, tree t) 6522{ 6523 fprintf (stream, "Class %s\n", type_as_string (t, TFF_PLAIN_IDENTIFIER)); 6524 fprintf (stream, " size=%lu align=%lu\n", 6525 (unsigned long)(tree_low_cst (TYPE_SIZE (t), 0) / BITS_PER_UNIT), 6526 (unsigned long)(TYPE_ALIGN (t) / BITS_PER_UNIT)); 6527 fprintf (stream, " base size=%lu base align=%lu\n", 6528 (unsigned long)(tree_low_cst (TYPE_SIZE (CLASSTYPE_AS_BASE (t)), 0) 6529 / BITS_PER_UNIT), 6530 (unsigned long)(TYPE_ALIGN (CLASSTYPE_AS_BASE (t)) 6531 / BITS_PER_UNIT)); 6532 dump_class_hierarchy_r (stream, flags, TYPE_BINFO (t), TYPE_BINFO (t), 0); 6533 fprintf (stream, "\n"); 6534} 6535 6536/* Debug interface to hierarchy dumping. */ 6537 6538extern void 6539debug_class (tree t) 6540{ 6541 dump_class_hierarchy_1 (stderr, TDF_SLIM, t); 6542} 6543 6544static void 6545dump_class_hierarchy (tree t) 6546{ 6547 int flags; 6548 FILE *stream = dump_begin (TDI_class, &flags); 6549 6550 if (stream) 6551 { 6552 dump_class_hierarchy_1 (stream, flags, t); 6553 dump_end (TDI_class, stream); 6554 } 6555} 6556 6557static void 6558dump_array (FILE * stream, tree decl) 6559{ 6560 tree value; 6561 unsigned HOST_WIDE_INT ix; 6562 HOST_WIDE_INT elt; 6563 tree size = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (decl))); 6564 6565 elt = (tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (decl))), 0) 6566 / BITS_PER_UNIT); 6567 fprintf (stream, "%s:", decl_as_string (decl, TFF_PLAIN_IDENTIFIER)); 6568 fprintf (stream, " %s entries", 6569 expr_as_string (size_binop (PLUS_EXPR, size, size_one_node), 6570 TFF_PLAIN_IDENTIFIER)); 6571 fprintf (stream, "\n"); 6572 6573 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (DECL_INITIAL (decl)), 6574 ix, value) 6575 fprintf (stream, "%-4ld %s\n", (long)(ix * elt), 6576 expr_as_string (value, TFF_PLAIN_IDENTIFIER)); 6577} 6578 6579static void 6580dump_vtable (tree t, tree binfo, tree vtable) 6581{ 6582 int flags; 6583 FILE *stream = dump_begin (TDI_class, &flags); 6584 6585 if (!stream) 6586 return; 6587 6588 if (!(flags & TDF_SLIM)) 6589 { 6590 int ctor_vtbl_p = TYPE_BINFO (t) != binfo; 6591 6592 fprintf (stream, "%s for %s", 6593 ctor_vtbl_p ? "Construction vtable" : "Vtable", 6594 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER)); 6595 if (ctor_vtbl_p) 6596 { 6597 if (!BINFO_VIRTUAL_P (binfo)) 6598 fprintf (stream, " (0x%lx instance)", (unsigned long)binfo); 6599 fprintf (stream, " in %s", type_as_string (t, TFF_PLAIN_IDENTIFIER)); 6600 } 6601 fprintf (stream, "\n"); 6602 dump_array (stream, vtable); 6603 fprintf (stream, "\n"); 6604 } 6605 6606 dump_end (TDI_class, stream); 6607} 6608 6609static void 6610dump_vtt (tree t, tree vtt) 6611{ 6612 int flags; 6613 FILE *stream = dump_begin (TDI_class, &flags); 6614 6615 if (!stream) 6616 return; 6617 6618 if (!(flags & TDF_SLIM)) 6619 { 6620 fprintf (stream, "VTT for %s\n", 6621 type_as_string (t, TFF_PLAIN_IDENTIFIER)); 6622 dump_array (stream, vtt); 6623 fprintf (stream, "\n"); 6624 } 6625 6626 dump_end (TDI_class, stream); 6627} 6628 6629/* Dump a function or thunk and its thunkees. */ 6630 6631static void 6632dump_thunk (FILE *stream, int indent, tree thunk) 6633{ 6634 static const char spaces[] = " "; 6635 tree name = DECL_NAME (thunk); 6636 tree thunks; 6637 6638 fprintf (stream, "%.*s%p %s %s", indent, spaces, 6639 (void *)thunk, 6640 !DECL_THUNK_P (thunk) ? "function" 6641 : DECL_THIS_THUNK_P (thunk) ? "this-thunk" : "covariant-thunk", 6642 name ? IDENTIFIER_POINTER (name) : "<unset>"); 6643 if (DECL_THUNK_P (thunk)) 6644 { 6645 HOST_WIDE_INT fixed_adjust = THUNK_FIXED_OFFSET (thunk); 6646 tree virtual_adjust = THUNK_VIRTUAL_OFFSET (thunk); 6647 6648 fprintf (stream, " fixed=" HOST_WIDE_INT_PRINT_DEC, fixed_adjust); 6649 if (!virtual_adjust) 6650 /*NOP*/; 6651 else if (DECL_THIS_THUNK_P (thunk)) 6652 fprintf (stream, " vcall=" HOST_WIDE_INT_PRINT_DEC, 6653 tree_low_cst (virtual_adjust, 0)); 6654 else 6655 fprintf (stream, " vbase=" HOST_WIDE_INT_PRINT_DEC "(%s)", 6656 tree_low_cst (BINFO_VPTR_FIELD (virtual_adjust), 0), 6657 type_as_string (BINFO_TYPE (virtual_adjust), TFF_SCOPE)); 6658 if (THUNK_ALIAS (thunk)) 6659 fprintf (stream, " alias to %p", (void *)THUNK_ALIAS (thunk)); 6660 } 6661 fprintf (stream, "\n"); 6662 for (thunks = DECL_THUNKS (thunk); thunks; thunks = TREE_CHAIN (thunks)) 6663 dump_thunk (stream, indent + 2, thunks); 6664} 6665 6666/* Dump the thunks for FN. */ 6667 6668extern void 6669debug_thunks (tree fn) 6670{ 6671 dump_thunk (stderr, 0, fn); 6672} 6673 6674/* Virtual function table initialization. */ 6675 6676/* Create all the necessary vtables for T and its base classes. */ 6677 6678static void 6679finish_vtbls (tree t) 6680{ 6681 tree list; 6682 tree vbase; 6683 6684 /* We lay out the primary and secondary vtables in one contiguous 6685 vtable. The primary vtable is first, followed by the non-virtual 6686 secondary vtables in inheritance graph order. */ 6687 list = build_tree_list (BINFO_VTABLE (TYPE_BINFO (t)), NULL_TREE); 6688 accumulate_vtbl_inits (TYPE_BINFO (t), TYPE_BINFO (t), 6689 TYPE_BINFO (t), t, list); 6690 6691 /* Then come the virtual bases, also in inheritance graph order. */ 6692 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase)) 6693 { 6694 if (!BINFO_VIRTUAL_P (vbase)) 6695 continue; 6696 accumulate_vtbl_inits (vbase, vbase, TYPE_BINFO (t), t, list); 6697 } 6698 6699 if (BINFO_VTABLE (TYPE_BINFO (t))) 6700 initialize_vtable (TYPE_BINFO (t), TREE_VALUE (list)); 6701} 6702 6703/* Initialize the vtable for BINFO with the INITS. */ 6704 6705static void 6706initialize_vtable (tree binfo, tree inits) 6707{ 6708 tree decl; 6709 6710 layout_vtable_decl (binfo, list_length (inits)); 6711 decl = get_vtbl_decl_for_binfo (binfo); 6712 initialize_artificial_var (decl, inits); 6713 dump_vtable (BINFO_TYPE (binfo), binfo, decl); 6714} 6715 6716/* Build the VTT (virtual table table) for T. 6717 A class requires a VTT if it has virtual bases. 6718 6719 This holds 6720 1 - primary virtual pointer for complete object T 6721 2 - secondary VTTs for each direct non-virtual base of T which requires a 6722 VTT 6723 3 - secondary virtual pointers for each direct or indirect base of T which 6724 has virtual bases or is reachable via a virtual path from T. 6725 4 - secondary VTTs for each direct or indirect virtual base of T. 6726 6727 Secondary VTTs look like complete object VTTs without part 4. */ 6728 6729static void 6730build_vtt (tree t) 6731{ 6732 tree inits; 6733 tree type; 6734 tree vtt; 6735 tree index; 6736 6737 /* Build up the initializers for the VTT. */ 6738 inits = NULL_TREE; 6739 index = size_zero_node; 6740 build_vtt_inits (TYPE_BINFO (t), t, &inits, &index); 6741 6742 /* If we didn't need a VTT, we're done. */ 6743 if (!inits) 6744 return; 6745 6746 /* Figure out the type of the VTT. */ 6747 type = build_index_type (size_int (list_length (inits) - 1)); 6748 type = build_cplus_array_type (const_ptr_type_node, type); 6749 6750 /* Now, build the VTT object itself. */ 6751 vtt = build_vtable (t, get_vtt_name (t), type); 6752 initialize_artificial_var (vtt, inits); 6753 /* Add the VTT to the vtables list. */ 6754 TREE_CHAIN (vtt) = TREE_CHAIN (CLASSTYPE_VTABLES (t)); 6755 TREE_CHAIN (CLASSTYPE_VTABLES (t)) = vtt; 6756 6757 dump_vtt (t, vtt); 6758} 6759 6760/* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with 6761 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo, 6762 and CHAIN the vtable pointer for this binfo after construction is 6763 complete. VALUE can also be another BINFO, in which case we recurse. */ 6764 6765static tree 6766binfo_ctor_vtable (tree binfo) 6767{ 6768 tree vt; 6769 6770 while (1) 6771 { 6772 vt = BINFO_VTABLE (binfo); 6773 if (TREE_CODE (vt) == TREE_LIST) 6774 vt = TREE_VALUE (vt); 6775 if (TREE_CODE (vt) == TREE_BINFO) 6776 binfo = vt; 6777 else 6778 break; 6779 } 6780 6781 return vt; 6782} 6783 6784/* Data for secondary VTT initialization. */ 6785typedef struct secondary_vptr_vtt_init_data_s 6786{ 6787 /* Is this the primary VTT? */ 6788 bool top_level_p; 6789 6790 /* Current index into the VTT. */ 6791 tree index; 6792 6793 /* TREE_LIST of initializers built up. */ 6794 tree inits; 6795 6796 /* The type being constructed by this secondary VTT. */ 6797 tree type_being_constructed; 6798} secondary_vptr_vtt_init_data; 6799 6800/* Recursively build the VTT-initializer for BINFO (which is in the 6801 hierarchy dominated by T). INITS points to the end of the initializer 6802 list to date. INDEX is the VTT index where the next element will be 6803 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e. 6804 not a subvtt for some base of T). When that is so, we emit the sub-VTTs 6805 for virtual bases of T. When it is not so, we build the constructor 6806 vtables for the BINFO-in-T variant. */ 6807 6808static tree * 6809build_vtt_inits (tree binfo, tree t, tree *inits, tree *index) 6810{ 6811 int i; 6812 tree b; 6813 tree init; 6814 tree secondary_vptrs; 6815 secondary_vptr_vtt_init_data data; 6816 int top_level_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t); 6817 6818 /* We only need VTTs for subobjects with virtual bases. */ 6819 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))) 6820 return inits; 6821 6822 /* We need to use a construction vtable if this is not the primary 6823 VTT. */ 6824 if (!top_level_p) 6825 { 6826 build_ctor_vtbl_group (binfo, t); 6827 6828 /* Record the offset in the VTT where this sub-VTT can be found. */ 6829 BINFO_SUBVTT_INDEX (binfo) = *index; 6830 } 6831 6832 /* Add the address of the primary vtable for the complete object. */ 6833 init = binfo_ctor_vtable (binfo); 6834 *inits = build_tree_list (NULL_TREE, init); 6835 inits = &TREE_CHAIN (*inits); 6836 if (top_level_p) 6837 { 6838 gcc_assert (!BINFO_VPTR_INDEX (binfo)); 6839 BINFO_VPTR_INDEX (binfo) = *index; 6840 } 6841 *index = size_binop (PLUS_EXPR, *index, TYPE_SIZE_UNIT (ptr_type_node)); 6842 6843 /* Recursively add the secondary VTTs for non-virtual bases. */ 6844 for (i = 0; BINFO_BASE_ITERATE (binfo, i, b); ++i) 6845 if (!BINFO_VIRTUAL_P (b)) 6846 inits = build_vtt_inits (b, t, inits, index); 6847 6848 /* Add secondary virtual pointers for all subobjects of BINFO with 6849 either virtual bases or reachable along a virtual path, except 6850 subobjects that are non-virtual primary bases. */ 6851 data.top_level_p = top_level_p; 6852 data.index = *index; 6853 data.inits = NULL; 6854 data.type_being_constructed = BINFO_TYPE (binfo); 6855 6856 dfs_walk_once (binfo, dfs_build_secondary_vptr_vtt_inits, NULL, &data); 6857 6858 *index = data.index; 6859 6860 /* The secondary vptrs come back in reverse order. After we reverse 6861 them, and add the INITS, the last init will be the first element 6862 of the chain. */ 6863 secondary_vptrs = data.inits; 6864 if (secondary_vptrs) 6865 { 6866 *inits = nreverse (secondary_vptrs); 6867 inits = &TREE_CHAIN (secondary_vptrs); 6868 gcc_assert (*inits == NULL_TREE); 6869 } 6870 6871 if (top_level_p) 6872 /* Add the secondary VTTs for virtual bases in inheritance graph 6873 order. */ 6874 for (b = TYPE_BINFO (BINFO_TYPE (binfo)); b; b = TREE_CHAIN (b)) 6875 { 6876 if (!BINFO_VIRTUAL_P (b)) 6877 continue; 6878 6879 inits = build_vtt_inits (b, t, inits, index); 6880 } 6881 else 6882 /* Remove the ctor vtables we created. */ 6883 dfs_walk_all (binfo, dfs_fixup_binfo_vtbls, NULL, binfo); 6884 6885 return inits; 6886} 6887 6888/* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base 6889 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */ 6890 6891static tree 6892dfs_build_secondary_vptr_vtt_inits (tree binfo, void *data_) 6893{ 6894 secondary_vptr_vtt_init_data *data = (secondary_vptr_vtt_init_data *)data_; 6895 6896 /* We don't care about bases that don't have vtables. */ 6897 if (!TYPE_VFIELD (BINFO_TYPE (binfo))) 6898 return dfs_skip_bases; 6899 6900 /* We're only interested in proper subobjects of the type being 6901 constructed. */ 6902 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->type_being_constructed)) 6903 return NULL_TREE; 6904 6905 /* We're only interested in bases with virtual bases or reachable 6906 via a virtual path from the type being constructed. */ 6907 if (!(CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)) 6908 || binfo_via_virtual (binfo, data->type_being_constructed))) 6909 return dfs_skip_bases; 6910 6911 /* We're not interested in non-virtual primary bases. */ 6912 if (!BINFO_VIRTUAL_P (binfo) && BINFO_PRIMARY_P (binfo)) 6913 return NULL_TREE; 6914 6915 /* Record the index where this secondary vptr can be found. */ 6916 if (data->top_level_p) 6917 { 6918 gcc_assert (!BINFO_VPTR_INDEX (binfo)); 6919 BINFO_VPTR_INDEX (binfo) = data->index; 6920 6921 if (BINFO_VIRTUAL_P (binfo)) 6922 { 6923 /* It's a primary virtual base, and this is not a 6924 construction vtable. Find the base this is primary of in 6925 the inheritance graph, and use that base's vtable 6926 now. */ 6927 while (BINFO_PRIMARY_P (binfo)) 6928 binfo = BINFO_INHERITANCE_CHAIN (binfo); 6929 } 6930 } 6931 6932 /* Add the initializer for the secondary vptr itself. */ 6933 data->inits = tree_cons (NULL_TREE, binfo_ctor_vtable (binfo), data->inits); 6934 6935 /* Advance the vtt index. */ 6936 data->index = size_binop (PLUS_EXPR, data->index, 6937 TYPE_SIZE_UNIT (ptr_type_node)); 6938 6939 return NULL_TREE; 6940} 6941 6942/* Called from build_vtt_inits via dfs_walk. After building 6943 constructor vtables and generating the sub-vtt from them, we need 6944 to restore the BINFO_VTABLES that were scribbled on. DATA is the 6945 binfo of the base whose sub vtt was generated. */ 6946 6947static tree 6948dfs_fixup_binfo_vtbls (tree binfo, void* data) 6949{ 6950 tree vtable = BINFO_VTABLE (binfo); 6951 6952 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))) 6953 /* If this class has no vtable, none of its bases do. */ 6954 return dfs_skip_bases; 6955 6956 if (!vtable) 6957 /* This might be a primary base, so have no vtable in this 6958 hierarchy. */ 6959 return NULL_TREE; 6960 6961 /* If we scribbled the construction vtable vptr into BINFO, clear it 6962 out now. */ 6963 if (TREE_CODE (vtable) == TREE_LIST 6964 && (TREE_PURPOSE (vtable) == (tree) data)) 6965 BINFO_VTABLE (binfo) = TREE_CHAIN (vtable); 6966 6967 return NULL_TREE; 6968} 6969 6970/* Build the construction vtable group for BINFO which is in the 6971 hierarchy dominated by T. */ 6972 6973static void 6974build_ctor_vtbl_group (tree binfo, tree t) 6975{ 6976 tree list; 6977 tree type; 6978 tree vtbl; 6979 tree inits; 6980 tree id; 6981 tree vbase; 6982 6983 /* See if we've already created this construction vtable group. */ 6984 id = mangle_ctor_vtbl_for_type (t, binfo); 6985 if (IDENTIFIER_GLOBAL_VALUE (id)) 6986 return; 6987 6988 gcc_assert (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t)); 6989 /* Build a version of VTBL (with the wrong type) for use in 6990 constructing the addresses of secondary vtables in the 6991 construction vtable group. */ 6992 vtbl = build_vtable (t, id, ptr_type_node); 6993 DECL_CONSTRUCTION_VTABLE_P (vtbl) = 1; 6994 list = build_tree_list (vtbl, NULL_TREE); 6995 accumulate_vtbl_inits (binfo, TYPE_BINFO (TREE_TYPE (binfo)), 6996 binfo, t, list); 6997 6998 /* Add the vtables for each of our virtual bases using the vbase in T 6999 binfo. */ 7000 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo)); 7001 vbase; 7002 vbase = TREE_CHAIN (vbase)) 7003 { 7004 tree b; 7005 7006 if (!BINFO_VIRTUAL_P (vbase)) 7007 continue; 7008 b = copied_binfo (vbase, binfo); 7009 7010 accumulate_vtbl_inits (b, vbase, binfo, t, list); 7011 } 7012 inits = TREE_VALUE (list); 7013 7014 /* Figure out the type of the construction vtable. */ 7015 type = build_index_type (size_int (list_length (inits) - 1)); 7016 type = build_cplus_array_type (vtable_entry_type, type); 7017 TREE_TYPE (vtbl) = type; 7018 7019 /* Initialize the construction vtable. */ 7020 CLASSTYPE_VTABLES (t) = chainon (CLASSTYPE_VTABLES (t), vtbl); 7021 initialize_artificial_var (vtbl, inits); 7022 dump_vtable (t, binfo, vtbl); 7023} 7024 7025/* Add the vtbl initializers for BINFO (and its bases other than 7026 non-virtual primaries) to the list of INITS. BINFO is in the 7027 hierarchy dominated by T. RTTI_BINFO is the binfo within T of 7028 the constructor the vtbl inits should be accumulated for. (If this 7029 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).) 7030 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO). 7031 BINFO is the active base equivalent of ORIG_BINFO in the inheritance 7032 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE, 7033 but are not necessarily the same in terms of layout. */ 7034 7035static void 7036accumulate_vtbl_inits (tree binfo, 7037 tree orig_binfo, 7038 tree rtti_binfo, 7039 tree t, 7040 tree inits) 7041{ 7042 int i; 7043 tree base_binfo; 7044 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t); 7045 7046 gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), BINFO_TYPE (orig_binfo))); 7047 7048 /* If it doesn't have a vptr, we don't do anything. */ 7049 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo))) 7050 return; 7051 7052 /* If we're building a construction vtable, we're not interested in 7053 subobjects that don't require construction vtables. */ 7054 if (ctor_vtbl_p 7055 && !CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)) 7056 && !binfo_via_virtual (orig_binfo, BINFO_TYPE (rtti_binfo))) 7057 return; 7058 7059 /* Build the initializers for the BINFO-in-T vtable. */ 7060 TREE_VALUE (inits) 7061 = chainon (TREE_VALUE (inits), 7062 dfs_accumulate_vtbl_inits (binfo, orig_binfo, 7063 rtti_binfo, t, inits)); 7064 7065 /* Walk the BINFO and its bases. We walk in preorder so that as we 7066 initialize each vtable we can figure out at what offset the 7067 secondary vtable lies from the primary vtable. We can't use 7068 dfs_walk here because we need to iterate through bases of BINFO 7069 and RTTI_BINFO simultaneously. */ 7070 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 7071 { 7072 /* Skip virtual bases. */ 7073 if (BINFO_VIRTUAL_P (base_binfo)) 7074 continue; 7075 accumulate_vtbl_inits (base_binfo, 7076 BINFO_BASE_BINFO (orig_binfo, i), 7077 rtti_binfo, t, 7078 inits); 7079 } 7080} 7081 7082/* Called from accumulate_vtbl_inits. Returns the initializers for 7083 the BINFO vtable. */ 7084 7085static tree 7086dfs_accumulate_vtbl_inits (tree binfo, 7087 tree orig_binfo, 7088 tree rtti_binfo, 7089 tree t, 7090 tree l) 7091{ 7092 tree inits = NULL_TREE; 7093 tree vtbl = NULL_TREE; 7094 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t); 7095 7096 if (ctor_vtbl_p 7097 && BINFO_VIRTUAL_P (orig_binfo) && BINFO_PRIMARY_P (orig_binfo)) 7098 { 7099 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a 7100 primary virtual base. If it is not the same primary in 7101 the hierarchy of T, we'll need to generate a ctor vtable 7102 for it, to place at its location in T. If it is the same 7103 primary, we still need a VTT entry for the vtable, but it 7104 should point to the ctor vtable for the base it is a 7105 primary for within the sub-hierarchy of RTTI_BINFO. 7106 7107 There are three possible cases: 7108 7109 1) We are in the same place. 7110 2) We are a primary base within a lost primary virtual base of 7111 RTTI_BINFO. 7112 3) We are primary to something not a base of RTTI_BINFO. */ 7113 7114 tree b; 7115 tree last = NULL_TREE; 7116 7117 /* First, look through the bases we are primary to for RTTI_BINFO 7118 or a virtual base. */ 7119 b = binfo; 7120 while (BINFO_PRIMARY_P (b)) 7121 { 7122 b = BINFO_INHERITANCE_CHAIN (b); 7123 last = b; 7124 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo) 7125 goto found; 7126 } 7127 /* If we run out of primary links, keep looking down our 7128 inheritance chain; we might be an indirect primary. */ 7129 for (b = last; b; b = BINFO_INHERITANCE_CHAIN (b)) 7130 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo) 7131 break; 7132 found: 7133 7134 /* If we found RTTI_BINFO, this is case 1. If we found a virtual 7135 base B and it is a base of RTTI_BINFO, this is case 2. In 7136 either case, we share our vtable with LAST, i.e. the 7137 derived-most base within B of which we are a primary. */ 7138 if (b == rtti_binfo 7139 || (b && binfo_for_vbase (BINFO_TYPE (b), BINFO_TYPE (rtti_binfo)))) 7140 /* Just set our BINFO_VTABLE to point to LAST, as we may not have 7141 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in 7142 binfo_ctor_vtable after everything's been set up. */ 7143 vtbl = last; 7144 7145 /* Otherwise, this is case 3 and we get our own. */ 7146 } 7147 else if (!BINFO_NEW_VTABLE_MARKED (orig_binfo)) 7148 return inits; 7149 7150 if (!vtbl) 7151 { 7152 tree index; 7153 int non_fn_entries; 7154 7155 /* Compute the initializer for this vtable. */ 7156 inits = build_vtbl_initializer (binfo, orig_binfo, t, rtti_binfo, 7157 &non_fn_entries); 7158 7159 /* Figure out the position to which the VPTR should point. */ 7160 vtbl = TREE_PURPOSE (l); 7161 vtbl = build1 (ADDR_EXPR, vtbl_ptr_type_node, vtbl); 7162 index = size_binop (PLUS_EXPR, 7163 size_int (non_fn_entries), 7164 size_int (list_length (TREE_VALUE (l)))); 7165 index = size_binop (MULT_EXPR, 7166 TYPE_SIZE_UNIT (vtable_entry_type), 7167 index); 7168 vtbl = build2 (PLUS_EXPR, TREE_TYPE (vtbl), vtbl, index); 7169 } 7170 7171 if (ctor_vtbl_p) 7172 /* For a construction vtable, we can't overwrite BINFO_VTABLE. 7173 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will 7174 straighten this out. */ 7175 BINFO_VTABLE (binfo) = tree_cons (rtti_binfo, vtbl, BINFO_VTABLE (binfo)); 7176 else if (BINFO_PRIMARY_P (binfo) && BINFO_VIRTUAL_P (binfo)) 7177 inits = NULL_TREE; 7178 else 7179 /* For an ordinary vtable, set BINFO_VTABLE. */ 7180 BINFO_VTABLE (binfo) = vtbl; 7181 7182 return inits; 7183} 7184 7185static GTY(()) tree abort_fndecl_addr; 7186 7187/* Construct the initializer for BINFO's virtual function table. BINFO 7188 is part of the hierarchy dominated by T. If we're building a 7189 construction vtable, the ORIG_BINFO is the binfo we should use to 7190 find the actual function pointers to put in the vtable - but they 7191 can be overridden on the path to most-derived in the graph that 7192 ORIG_BINFO belongs. Otherwise, 7193 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the 7194 BINFO that should be indicated by the RTTI information in the 7195 vtable; it will be a base class of T, rather than T itself, if we 7196 are building a construction vtable. 7197 7198 The value returned is a TREE_LIST suitable for wrapping in a 7199 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If 7200 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the 7201 number of non-function entries in the vtable. 7202 7203 It might seem that this function should never be called with a 7204 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a 7205 base is always subsumed by a derived class vtable. However, when 7206 we are building construction vtables, we do build vtables for 7207 primary bases; we need these while the primary base is being 7208 constructed. */ 7209 7210static tree 7211build_vtbl_initializer (tree binfo, 7212 tree orig_binfo, 7213 tree t, 7214 tree rtti_binfo, 7215 int* non_fn_entries_p) 7216{ 7217 tree v, b; 7218 tree vfun_inits; 7219 vtbl_init_data vid; 7220 unsigned ix; 7221 tree vbinfo; 7222 VEC(tree,gc) *vbases; 7223 7224 /* Initialize VID. */ 7225 memset (&vid, 0, sizeof (vid)); 7226 vid.binfo = binfo; 7227 vid.derived = t; 7228 vid.rtti_binfo = rtti_binfo; 7229 vid.last_init = &vid.inits; 7230 vid.primary_vtbl_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t); 7231 vid.ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t); 7232 vid.generate_vcall_entries = true; 7233 /* The first vbase or vcall offset is at index -3 in the vtable. */ 7234 vid.index = ssize_int(-3 * TARGET_VTABLE_DATA_ENTRY_DISTANCE); 7235 7236 /* Add entries to the vtable for RTTI. */ 7237 build_rtti_vtbl_entries (binfo, &vid); 7238 7239 /* Create an array for keeping track of the functions we've 7240 processed. When we see multiple functions with the same 7241 signature, we share the vcall offsets. */ 7242 vid.fns = VEC_alloc (tree, gc, 32); 7243 /* Add the vcall and vbase offset entries. */ 7244 build_vcall_and_vbase_vtbl_entries (binfo, &vid); 7245 7246 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by 7247 build_vbase_offset_vtbl_entries. */ 7248 for (vbases = CLASSTYPE_VBASECLASSES (t), ix = 0; 7249 VEC_iterate (tree, vbases, ix, vbinfo); ix++) 7250 BINFO_VTABLE_PATH_MARKED (vbinfo) = 0; 7251 7252 /* If the target requires padding between data entries, add that now. */ 7253 if (TARGET_VTABLE_DATA_ENTRY_DISTANCE > 1) 7254 { 7255 tree cur, *prev; 7256 7257 for (prev = &vid.inits; (cur = *prev); prev = &TREE_CHAIN (cur)) 7258 { 7259 tree add = cur; 7260 int i; 7261 7262 for (i = 1; i < TARGET_VTABLE_DATA_ENTRY_DISTANCE; ++i) 7263 add = tree_cons (NULL_TREE, 7264 build1 (NOP_EXPR, vtable_entry_type, 7265 null_pointer_node), 7266 add); 7267 *prev = add; 7268 } 7269 } 7270 7271 if (non_fn_entries_p) 7272 *non_fn_entries_p = list_length (vid.inits); 7273 7274 /* Go through all the ordinary virtual functions, building up 7275 initializers. */ 7276 vfun_inits = NULL_TREE; 7277 for (v = BINFO_VIRTUALS (orig_binfo); v; v = TREE_CHAIN (v)) 7278 { 7279 tree delta; 7280 tree vcall_index; 7281 tree fn, fn_original; 7282 tree init = NULL_TREE; 7283 7284 fn = BV_FN (v); 7285 fn_original = fn; 7286 if (DECL_THUNK_P (fn)) 7287 { 7288 if (!DECL_NAME (fn)) 7289 finish_thunk (fn); 7290 if (THUNK_ALIAS (fn)) 7291 { 7292 fn = THUNK_ALIAS (fn); 7293 BV_FN (v) = fn; 7294 } 7295 fn_original = THUNK_TARGET (fn); 7296 } 7297 7298 /* If the only definition of this function signature along our 7299 primary base chain is from a lost primary, this vtable slot will 7300 never be used, so just zero it out. This is important to avoid 7301 requiring extra thunks which cannot be generated with the function. 7302 7303 We first check this in update_vtable_entry_for_fn, so we handle 7304 restored primary bases properly; we also need to do it here so we 7305 zero out unused slots in ctor vtables, rather than filling themff 7306 with erroneous values (though harmless, apart from relocation 7307 costs). */ 7308 for (b = binfo; ; b = get_primary_binfo (b)) 7309 { 7310 /* We found a defn before a lost primary; go ahead as normal. */ 7311 if (look_for_overrides_here (BINFO_TYPE (b), fn_original)) 7312 break; 7313 7314 /* The nearest definition is from a lost primary; clear the 7315 slot. */ 7316 if (BINFO_LOST_PRIMARY_P (b)) 7317 { 7318 init = size_zero_node; 7319 break; 7320 } 7321 } 7322 7323 if (! init) 7324 { 7325 /* Pull the offset for `this', and the function to call, out of 7326 the list. */ 7327 delta = BV_DELTA (v); 7328 vcall_index = BV_VCALL_INDEX (v); 7329 7330 gcc_assert (TREE_CODE (delta) == INTEGER_CST); 7331 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); 7332 7333 /* You can't call an abstract virtual function; it's abstract. 7334 So, we replace these functions with __pure_virtual. */ 7335 if (DECL_PURE_VIRTUAL_P (fn_original)) 7336 { 7337 fn = abort_fndecl; 7338 if (abort_fndecl_addr == NULL) 7339 abort_fndecl_addr = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn); 7340 init = abort_fndecl_addr; 7341 } 7342 else 7343 { 7344 if (!integer_zerop (delta) || vcall_index) 7345 { 7346 fn = make_thunk (fn, /*this_adjusting=*/1, delta, vcall_index); 7347 if (!DECL_NAME (fn)) 7348 finish_thunk (fn); 7349 } 7350 /* Take the address of the function, considering it to be of an 7351 appropriate generic type. */ 7352 init = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn); 7353 } 7354 } 7355 7356 /* And add it to the chain of initializers. */ 7357 if (TARGET_VTABLE_USES_DESCRIPTORS) 7358 { 7359 int i; 7360 if (init == size_zero_node) 7361 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i) 7362 vfun_inits = tree_cons (NULL_TREE, init, vfun_inits); 7363 else 7364 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i) 7365 { 7366 tree fdesc = build2 (FDESC_EXPR, vfunc_ptr_type_node, 7367 TREE_OPERAND (init, 0), 7368 build_int_cst (NULL_TREE, i)); 7369 TREE_CONSTANT (fdesc) = 1; 7370 TREE_INVARIANT (fdesc) = 1; 7371 7372 vfun_inits = tree_cons (NULL_TREE, fdesc, vfun_inits); 7373 } 7374 } 7375 else 7376 vfun_inits = tree_cons (NULL_TREE, init, vfun_inits); 7377 } 7378 7379 /* The initializers for virtual functions were built up in reverse 7380 order; straighten them out now. */ 7381 vfun_inits = nreverse (vfun_inits); 7382 7383 /* The negative offset initializers are also in reverse order. */ 7384 vid.inits = nreverse (vid.inits); 7385 7386 /* Chain the two together. */ 7387 return chainon (vid.inits, vfun_inits); 7388} 7389 7390/* Adds to vid->inits the initializers for the vbase and vcall 7391 offsets in BINFO, which is in the hierarchy dominated by T. */ 7392 7393static void 7394build_vcall_and_vbase_vtbl_entries (tree binfo, vtbl_init_data* vid) 7395{ 7396 tree b; 7397 7398 /* If this is a derived class, we must first create entries 7399 corresponding to the primary base class. */ 7400 b = get_primary_binfo (binfo); 7401 if (b) 7402 build_vcall_and_vbase_vtbl_entries (b, vid); 7403 7404 /* Add the vbase entries for this base. */ 7405 build_vbase_offset_vtbl_entries (binfo, vid); 7406 /* Add the vcall entries for this base. */ 7407 build_vcall_offset_vtbl_entries (binfo, vid); 7408} 7409 7410/* Returns the initializers for the vbase offset entries in the vtable 7411 for BINFO (which is part of the class hierarchy dominated by T), in 7412 reverse order. VBASE_OFFSET_INDEX gives the vtable index 7413 where the next vbase offset will go. */ 7414 7415static void 7416build_vbase_offset_vtbl_entries (tree binfo, vtbl_init_data* vid) 7417{ 7418 tree vbase; 7419 tree t; 7420 tree non_primary_binfo; 7421 7422 /* If there are no virtual baseclasses, then there is nothing to 7423 do. */ 7424 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))) 7425 return; 7426 7427 t = vid->derived; 7428 7429 /* We might be a primary base class. Go up the inheritance hierarchy 7430 until we find the most derived class of which we are a primary base: 7431 it is the offset of that which we need to use. */ 7432 non_primary_binfo = binfo; 7433 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo)) 7434 { 7435 tree b; 7436 7437 /* If we have reached a virtual base, then it must be a primary 7438 base (possibly multi-level) of vid->binfo, or we wouldn't 7439 have called build_vcall_and_vbase_vtbl_entries for it. But it 7440 might be a lost primary, so just skip down to vid->binfo. */ 7441 if (BINFO_VIRTUAL_P (non_primary_binfo)) 7442 { 7443 non_primary_binfo = vid->binfo; 7444 break; 7445 } 7446 7447 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo); 7448 if (get_primary_binfo (b) != non_primary_binfo) 7449 break; 7450 non_primary_binfo = b; 7451 } 7452 7453 /* Go through the virtual bases, adding the offsets. */ 7454 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo)); 7455 vbase; 7456 vbase = TREE_CHAIN (vbase)) 7457 { 7458 tree b; 7459 tree delta; 7460 7461 if (!BINFO_VIRTUAL_P (vbase)) 7462 continue; 7463 7464 /* Find the instance of this virtual base in the complete 7465 object. */ 7466 b = copied_binfo (vbase, binfo); 7467 7468 /* If we've already got an offset for this virtual base, we 7469 don't need another one. */ 7470 if (BINFO_VTABLE_PATH_MARKED (b)) 7471 continue; 7472 BINFO_VTABLE_PATH_MARKED (b) = 1; 7473 7474 /* Figure out where we can find this vbase offset. */ 7475 delta = size_binop (MULT_EXPR, 7476 vid->index, 7477 convert (ssizetype, 7478 TYPE_SIZE_UNIT (vtable_entry_type))); 7479 if (vid->primary_vtbl_p) 7480 BINFO_VPTR_FIELD (b) = delta; 7481 7482 if (binfo != TYPE_BINFO (t)) 7483 /* The vbase offset had better be the same. */ 7484 gcc_assert (tree_int_cst_equal (delta, BINFO_VPTR_FIELD (vbase))); 7485 7486 /* The next vbase will come at a more negative offset. */ 7487 vid->index = size_binop (MINUS_EXPR, vid->index, 7488 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE)); 7489 7490 /* The initializer is the delta from BINFO to this virtual base. 7491 The vbase offsets go in reverse inheritance-graph order, and 7492 we are walking in inheritance graph order so these end up in 7493 the right order. */ 7494 delta = size_diffop (BINFO_OFFSET (b), BINFO_OFFSET (non_primary_binfo)); 7495 7496 *vid->last_init 7497 = build_tree_list (NULL_TREE, 7498 fold_build1 (NOP_EXPR, 7499 vtable_entry_type, 7500 delta)); 7501 vid->last_init = &TREE_CHAIN (*vid->last_init); 7502 } 7503} 7504 7505/* Adds the initializers for the vcall offset entries in the vtable 7506 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED) 7507 to VID->INITS. */ 7508 7509static void 7510build_vcall_offset_vtbl_entries (tree binfo, vtbl_init_data* vid) 7511{ 7512 /* We only need these entries if this base is a virtual base. We 7513 compute the indices -- but do not add to the vtable -- when 7514 building the main vtable for a class. */ 7515 if (BINFO_VIRTUAL_P (binfo) || binfo == TYPE_BINFO (vid->derived)) 7516 { 7517 /* We need a vcall offset for each of the virtual functions in this 7518 vtable. For example: 7519 7520 class A { virtual void f (); }; 7521 class B1 : virtual public A { virtual void f (); }; 7522 class B2 : virtual public A { virtual void f (); }; 7523 class C: public B1, public B2 { virtual void f (); }; 7524 7525 A C object has a primary base of B1, which has a primary base of A. A 7526 C also has a secondary base of B2, which no longer has a primary base 7527 of A. So the B2-in-C construction vtable needs a secondary vtable for 7528 A, which will adjust the A* to a B2* to call f. We have no way of 7529 knowing what (or even whether) this offset will be when we define B2, 7530 so we store this "vcall offset" in the A sub-vtable and look it up in 7531 a "virtual thunk" for B2::f. 7532 7533 We need entries for all the functions in our primary vtable and 7534 in our non-virtual bases' secondary vtables. */ 7535 vid->vbase = binfo; 7536 /* If we are just computing the vcall indices -- but do not need 7537 the actual entries -- not that. */ 7538 if (!BINFO_VIRTUAL_P (binfo)) 7539 vid->generate_vcall_entries = false; 7540 /* Now, walk through the non-virtual bases, adding vcall offsets. */ 7541 add_vcall_offset_vtbl_entries_r (binfo, vid); 7542 } 7543} 7544 7545/* Build vcall offsets, starting with those for BINFO. */ 7546 7547static void 7548add_vcall_offset_vtbl_entries_r (tree binfo, vtbl_init_data* vid) 7549{ 7550 int i; 7551 tree primary_binfo; 7552 tree base_binfo; 7553 7554 /* Don't walk into virtual bases -- except, of course, for the 7555 virtual base for which we are building vcall offsets. Any 7556 primary virtual base will have already had its offsets generated 7557 through the recursion in build_vcall_and_vbase_vtbl_entries. */ 7558 if (BINFO_VIRTUAL_P (binfo) && vid->vbase != binfo) 7559 return; 7560 7561 /* If BINFO has a primary base, process it first. */ 7562 primary_binfo = get_primary_binfo (binfo); 7563 if (primary_binfo) 7564 add_vcall_offset_vtbl_entries_r (primary_binfo, vid); 7565 7566 /* Add BINFO itself to the list. */ 7567 add_vcall_offset_vtbl_entries_1 (binfo, vid); 7568 7569 /* Scan the non-primary bases of BINFO. */ 7570 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i) 7571 if (base_binfo != primary_binfo) 7572 add_vcall_offset_vtbl_entries_r (base_binfo, vid); 7573} 7574 7575/* Called from build_vcall_offset_vtbl_entries_r. */ 7576 7577static void 7578add_vcall_offset_vtbl_entries_1 (tree binfo, vtbl_init_data* vid) 7579{ 7580 /* Make entries for the rest of the virtuals. */ 7581 if (abi_version_at_least (2)) 7582 { 7583 tree orig_fn; 7584 7585 /* The ABI requires that the methods be processed in declaration 7586 order. G++ 3.2 used the order in the vtable. */ 7587 for (orig_fn = TYPE_METHODS (BINFO_TYPE (binfo)); 7588 orig_fn; 7589 orig_fn = TREE_CHAIN (orig_fn)) 7590 if (DECL_VINDEX (orig_fn)) 7591 add_vcall_offset (orig_fn, binfo, vid); 7592 } 7593 else 7594 { 7595 tree derived_virtuals; 7596 tree base_virtuals; 7597 tree orig_virtuals; 7598 /* If BINFO is a primary base, the most derived class which has 7599 BINFO as a primary base; otherwise, just BINFO. */ 7600 tree non_primary_binfo; 7601 7602 /* We might be a primary base class. Go up the inheritance hierarchy 7603 until we find the most derived class of which we are a primary base: 7604 it is the BINFO_VIRTUALS there that we need to consider. */ 7605 non_primary_binfo = binfo; 7606 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo)) 7607 { 7608 tree b; 7609 7610 /* If we have reached a virtual base, then it must be vid->vbase, 7611 because we ignore other virtual bases in 7612 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary 7613 base (possibly multi-level) of vid->binfo, or we wouldn't 7614 have called build_vcall_and_vbase_vtbl_entries for it. But it 7615 might be a lost primary, so just skip down to vid->binfo. */ 7616 if (BINFO_VIRTUAL_P (non_primary_binfo)) 7617 { 7618 gcc_assert (non_primary_binfo == vid->vbase); 7619 non_primary_binfo = vid->binfo; 7620 break; 7621 } 7622 7623 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo); 7624 if (get_primary_binfo (b) != non_primary_binfo) 7625 break; 7626 non_primary_binfo = b; 7627 } 7628 7629 if (vid->ctor_vtbl_p) 7630 /* For a ctor vtable we need the equivalent binfo within the hierarchy 7631 where rtti_binfo is the most derived type. */ 7632 non_primary_binfo 7633 = original_binfo (non_primary_binfo, vid->rtti_binfo); 7634 7635 for (base_virtuals = BINFO_VIRTUALS (binfo), 7636 derived_virtuals = BINFO_VIRTUALS (non_primary_binfo), 7637 orig_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo))); 7638 base_virtuals; 7639 base_virtuals = TREE_CHAIN (base_virtuals), 7640 derived_virtuals = TREE_CHAIN (derived_virtuals), 7641 orig_virtuals = TREE_CHAIN (orig_virtuals)) 7642 { 7643 tree orig_fn; 7644 7645 /* Find the declaration that originally caused this function to 7646 be present in BINFO_TYPE (binfo). */ 7647 orig_fn = BV_FN (orig_virtuals); 7648 7649 /* When processing BINFO, we only want to generate vcall slots for 7650 function slots introduced in BINFO. So don't try to generate 7651 one if the function isn't even defined in BINFO. */ 7652 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), DECL_CONTEXT (orig_fn))) 7653 continue; 7654 7655 add_vcall_offset (orig_fn, binfo, vid); 7656 } 7657 } 7658} 7659 7660/* Add a vcall offset entry for ORIG_FN to the vtable. */ 7661 7662static void 7663add_vcall_offset (tree orig_fn, tree binfo, vtbl_init_data *vid) 7664{ 7665 size_t i; 7666 tree vcall_offset; 7667 tree derived_entry; 7668 7669 /* If there is already an entry for a function with the same 7670 signature as FN, then we do not need a second vcall offset. 7671 Check the list of functions already present in the derived 7672 class vtable. */ 7673 for (i = 0; VEC_iterate (tree, vid->fns, i, derived_entry); ++i) 7674 { 7675 if (same_signature_p (derived_entry, orig_fn) 7676 /* We only use one vcall offset for virtual destructors, 7677 even though there are two virtual table entries. */ 7678 || (DECL_DESTRUCTOR_P (derived_entry) 7679 && DECL_DESTRUCTOR_P (orig_fn))) 7680 return; 7681 } 7682 7683 /* If we are building these vcall offsets as part of building 7684 the vtable for the most derived class, remember the vcall 7685 offset. */ 7686 if (vid->binfo == TYPE_BINFO (vid->derived)) 7687 { 7688 tree_pair_p elt = VEC_safe_push (tree_pair_s, gc, 7689 CLASSTYPE_VCALL_INDICES (vid->derived), 7690 NULL); 7691 elt->purpose = orig_fn; 7692 elt->value = vid->index; 7693 } 7694 7695 /* The next vcall offset will be found at a more negative 7696 offset. */ 7697 vid->index = size_binop (MINUS_EXPR, vid->index, 7698 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE)); 7699 7700 /* Keep track of this function. */ 7701 VEC_safe_push (tree, gc, vid->fns, orig_fn); 7702 7703 if (vid->generate_vcall_entries) 7704 { 7705 tree base; 7706 tree fn; 7707 7708 /* Find the overriding function. */ 7709 fn = find_final_overrider (vid->rtti_binfo, binfo, orig_fn); 7710 if (fn == error_mark_node) 7711 vcall_offset = build1 (NOP_EXPR, vtable_entry_type, 7712 integer_zero_node); 7713 else 7714 { 7715 base = TREE_VALUE (fn); 7716 7717 /* The vbase we're working on is a primary base of 7718 vid->binfo. But it might be a lost primary, so its 7719 BINFO_OFFSET might be wrong, so we just use the 7720 BINFO_OFFSET from vid->binfo. */ 7721 vcall_offset = size_diffop (BINFO_OFFSET (base), 7722 BINFO_OFFSET (vid->binfo)); 7723 vcall_offset = fold_build1 (NOP_EXPR, vtable_entry_type, 7724 vcall_offset); 7725 } 7726 /* Add the initializer to the vtable. */ 7727 *vid->last_init = build_tree_list (NULL_TREE, vcall_offset); 7728 vid->last_init = &TREE_CHAIN (*vid->last_init); 7729 } 7730} 7731 7732/* Return vtbl initializers for the RTTI entries corresponding to the 7733 BINFO's vtable. The RTTI entries should indicate the object given 7734 by VID->rtti_binfo. */ 7735 7736static void 7737build_rtti_vtbl_entries (tree binfo, vtbl_init_data* vid) 7738{ 7739 tree b; 7740 tree t; 7741 tree basetype; 7742 tree offset; 7743 tree decl; 7744 tree init; 7745 7746 basetype = BINFO_TYPE (binfo); 7747 t = BINFO_TYPE (vid->rtti_binfo); 7748 7749 /* To find the complete object, we will first convert to our most 7750 primary base, and then add the offset in the vtbl to that value. */ 7751 b = binfo; 7752 while (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (b)) 7753 && !BINFO_LOST_PRIMARY_P (b)) 7754 { 7755 tree primary_base; 7756 7757 primary_base = get_primary_binfo (b); 7758 gcc_assert (BINFO_PRIMARY_P (primary_base) 7759 && BINFO_INHERITANCE_CHAIN (primary_base) == b); 7760 b = primary_base; 7761 } 7762 offset = size_diffop (BINFO_OFFSET (vid->rtti_binfo), BINFO_OFFSET (b)); 7763 7764 /* The second entry is the address of the typeinfo object. */ 7765 if (flag_rtti) 7766 decl = build_address (get_tinfo_decl (t)); 7767 else 7768 decl = integer_zero_node; 7769 7770 /* Convert the declaration to a type that can be stored in the 7771 vtable. */ 7772 init = build_nop (vfunc_ptr_type_node, decl); 7773 *vid->last_init = build_tree_list (NULL_TREE, init); 7774 vid->last_init = &TREE_CHAIN (*vid->last_init); 7775 7776 /* Add the offset-to-top entry. It comes earlier in the vtable than 7777 the typeinfo entry. Convert the offset to look like a 7778 function pointer, so that we can put it in the vtable. */ 7779 init = build_nop (vfunc_ptr_type_node, offset); 7780 *vid->last_init = build_tree_list (NULL_TREE, init); 7781 vid->last_init = &TREE_CHAIN (*vid->last_init); 7782} 7783 7784/* Fold a OBJ_TYPE_REF expression to the address of a function. 7785 KNOWN_TYPE carries the true type of OBJ_TYPE_REF_OBJECT(REF). */ 7786 7787tree 7788cp_fold_obj_type_ref (tree ref, tree known_type) 7789{ 7790 HOST_WIDE_INT index = tree_low_cst (OBJ_TYPE_REF_TOKEN (ref), 1); 7791 HOST_WIDE_INT i = 0; 7792 tree v = BINFO_VIRTUALS (TYPE_BINFO (known_type)); 7793 tree fndecl; 7794 7795 while (i != index) 7796 { 7797 i += (TARGET_VTABLE_USES_DESCRIPTORS 7798 ? TARGET_VTABLE_USES_DESCRIPTORS : 1); 7799 v = TREE_CHAIN (v); 7800 } 7801 7802 fndecl = BV_FN (v); 7803 7804#ifdef ENABLE_CHECKING 7805 gcc_assert (tree_int_cst_equal (OBJ_TYPE_REF_TOKEN (ref), 7806 DECL_VINDEX (fndecl))); 7807#endif 7808 7809 cgraph_node (fndecl)->local.vtable_method = true; 7810 7811 return build_address (fndecl); 7812} 7813 7814#include "gt-cp-class.h" 7815